Guide to buying Centra (CTR) ICO


Apr 14th 2017
As many of you may have heard Floyd Mayweather is promoting his 3rd ICO ( Centra is the next ICO that is targeting the crypto debit card market and is being run on the Ethereum network, and have just joined the Ethereum Alliance ( The Centra team says if you contribute at least 5 ETH you will get a free Centra debit card which you can start using as soon as you receive it (

So, I've compiled a short guide for those who wish to buy in, while you still can. The Bonus offerings during the early pre sale of Centra are unfortunately over, but right now 1 ETH will buy you 200 CTR's so it may not be a bad investment for people who like to gamble on the ICO market.

So here we go...
**You must first have a ETH wallet set up on one of the wallets listed on their website before you can buy in (MyEtherWallet, Metamask, Parity, Mist or Ledger (hardware wallet)). They will not accept ETH from exchanges like Coinbase, etc. So if you have a wallet set up with one of these above mentioned wallets then ignore step one.
**Here is a good video that will walk you through setting up the MyEther Wallet. ( However, there are a few steps in the following instructions that are specific to Centra that this video won't cover.

1. Set up a wallet at one of the above listed wallet platforms. For this guide I will use MyEtherWallet. First go to You will be met with a screen telling you to create a new wallet by first entering a password. You choose any password you want and don't forget it; and store it somewhere safe. Once you've entered the password, click the Create New Wallet button. Next you will be prompted to Save Your Wallet File, by downloading a Keystore File. This is essentially just a file that you will be prompted to open every time you want to access your wallet. The Keystore File holds your public and private key which will be accessible via the password you chose when you created the wallet. Click the Download button and choose where you want to save it. Make sure you save it somewhere you can find it easily but that is also still secure. The next screen will show your private key. At this point you will have the option to Print a paper wallet which will contain all the relevant information about your wallet. I highly suggest printing it and storing it somewhere secure. After you have printed your paper wallet, return to the MyEtherWallet tab and click on the Next:Save your Address button. This will take you to a screen that says "Unlock your wallet to see your address," and will have options below asking how you would like to access your wallet; but if you'll notice you are under the Generate Wallet tab. Since you've already generated a wallet you will want to click on the tab next to the Generate Wallet tab which says Send Ether and Tokens. The same options should show below. Since you downloaded the Keystore File, select the Keystore File (UTC/JSON) button. Once you click on the button, to the right it will ask you to Select Your Wallet File with a button just below it that says Select Wallet File. Click the Select Wallet File button and it will prompt you to select which file you are trying to open from. This is where you will look for your Keystore File that you downloaded earlier (the file will generally begin with the letters UTC). Once you've selected it click Open. Once selected it will ask you to enter your password, which is the password you created in the beginning to generate your wallet. Once you've entered your password click on the Unlock button to unlock your wallet. It will then take you to a screen that will show your MyEtherWallet address and also the ability to send ETH out of your wallet.
2. Next you will copy your MyEtherWallet address, open Coinbase or whatever other exchange/wallet where your ETH is stored, and in the send tab in Coinbase,etc. enter or paste your MyEtherWallet address, choose the amount you wish to send and send it. The transaction should be relatively quick and you can verify it using the website, which will be listed under your account address under Transaction History. ***Remember, there is a transaction fee out of the wallet where your ETH is stored and another fee going out of MyEtherWallet, so you'll need to calculate or estimate that fee in order to have enough to buy the proper amount of Centra. For instance, if you want to spend 5 ETH to get the free Centra debit card you'll have to send about 5.002 ETH from Coinbase (et al) to MyEtherWallet. Once your transaction clears you should now be able to see an ETH balance in your MyEtherWallet. You may need to refresh your screen to see it and usually it will prompt you to reopen your wallet (if so simply follow the same steps listed earlier to open your wallet).
3. Before buying CTR you will need to create a Token on MyEtherWallet where your CTR can be deposited and stored after sending your ETH to Centra. To do this look below Token Balances on your wallet under the Send Ether and Tokens tab and you will see a button that says Show Tokens and next to that a button that says Add Custom Token. Click on Add Custom Token and it will ask you to enter an address, token symbol, and decimals. Go to this link to find this information ( If the link doesn't work simply search for Centra on the page. There it will show Centra's profile including a Contract Address (which is the address you will put in the Address bar for your Custom Token). For the Token Symbol you will type CTR, and for the Decimals, as it shows on the etherscan Centra profile, enter 18. Once you have all three fields properly filled in click Save. Once saved you can click on Show Tokens and it will show all the tokens listed on the ETH network and will show your new custom token, CTR, at the bottom of the list (most likely).
4. Now that you have a CTR Custom Token, and your desired ETH balance showing in your wallet, you can now send your ETH to Centra to obtain the Centra token amount relevant to the amount of ETH you spend. As I stated earlier, you will have to have a little bit more ETH in your wallet than you wish to send to cover the transaction fee. To know exactly what the transaction fee will be you have to first set the parameters that Centra has outlined on their website. These include the following: - Set Gas Limit to 200,000, - Set the gas price at 50 GWEI, - 200 CTR Tokens / 1 ETH. To do this, first set the Gas Price to 50 GWEI. Above your Address Account number you should see three tabs with drop down menus. One will be for language (English) next to that is the Gas Price, and next to that is the Network (ETH). Make sure the Network is set to ETH (it will be by default), choose your language (English is default), and then choose your Gas Price from the drop down menu. The Gas Price default is usually set to 20 GWEI. All this means is that you're changing the transaction fee to a higher fee. The higher fee will generally ensure quicker transaction times. Generally 20 or less is fine when using the network to make other transactions, but since Centra is requiring you to make the GWEI 50 then you must make it 50. Next you will adjust the Gas Limit which is the field below the Send to address, and Set to amount. The default Gas Limit is set to 21,000. Change this to 200,000 which is what Centra requires. Generally token specific sales will require a Gas Limit of 200,000. Next enter the amount you want to send to Centra by typing it in, remember that there is a network fee so one easy way to figure out what it is would be to click on the Send Entire Balance button just below the Send to Amount field. This will show you how much you can send minus the transaction fee. If you subtract that amount from your actual balance, that is the fee. Example- If I have 5 ETH in my MyEtherWallet wallet, and I want to send 5 ETH to Centra, minus the transaction fee (with Centra's required parameters set) I could only send about 4.99.... (whatever-depending on the network fee). So to send an even 5 ETH, it would likely cost me about 5.002 ETH, so make sure you have enough in your MyEtherWallet because if you are trying to obtain the free debit card from Centra you'll need to send at least 5 ETH, not 4.9999999, etc. ETH. So, once you've set the Gas Price to 50 GWEI, and the Gas Limit to 200,000, and your amount to (whatever you want to send, minus the fee), now you will go to Centra's token sale website ( and from there click on Show Address. A pop up screen will appear and will take you through some basic terms and conditions and ask you to check off that you have read and understood them and sign your name. Since there are no name specific sign ups with Centra I'm not sure why they need your name, but it's up to you what you want to put in the name field. I'm pretty sure you'll get the tokens one way or the other since the address is what is important. But after you agree to the terms and conditions it will show the address, however, I'm not sure if it's just a temporary glitch but it shows the same address below anyway, so you may want to just skip the signing part. The send to address listed on their website as of now is: 0xbDB45d02D8eF8dc5E59aa58B26b99A4af3806bAa. However, make sure this is still correct at the time you wish to buy. There have already been several scam artists trying to pose as Centra by creating fake profiles that look very similar to Centra but are not related to Centra. They provide an address that is not related to Centra in the hopes that people will send their ETH to them, ie scam... so beware. But if you look on the above Centra Token sale website they will say Only Send ETH to: and list the address; use the address they list on their official site. Once you've obtained the correct address, copy it, then paste it in the Send to field from your MyEtherWallet. Once everything looks good and you're ready to send, click the Generate Transaction, then it will ask you to Send the Transaction provided it looks correct (it may ask you again if the transaction is correct for final approval; once again if it is, then verify it). Once the transaction has been sent it will provide a link back to the website so you can check the status of your transaction. You can click the link to make sure that the transaction was recorded on the blockchain. After that, go back to your MyEtherWallet and verify that your balance has changed, it may take a few minutes or more. Once it goes through you should be able to click on Show Tokens again, and scroll down to see a CTR balance. Also if you click on the Show Balances button it should show whatever tokens you have balances in and what the balances are.

And that's it. If you did everything right you should have a CTR balance. Now, because the coin itself hasn't launched yet you are not technically buying CTR coins. What you are buying are ERC20 tokens on the Ethereum Network. If you don't know what an ERC20 token is then I suggest doing a little research to learn what they are. In a nutshell an ERC20 token is simply an IOU on the Ethereum Network. You're basically paying for promises. Sound risky? Well, that's the double edged sword of buying ICO's. They could pay off big, or you could lose everything, so choose wisely. But provided the company does what they say they will do, buying an ERC20 token should provide you with a promised amount of their coin once it launches and a wallet is available for use, in exchange for whatever coin you used to buy into the ICO, in this case ETH, and the smart contracts should execute the coin transfer to all investors once the coin goes live and there is a wallet to send them to. As for Centra, they are promising tokens and, if you invest at least 5 ETH, a basic crypto debit card. Some people have uploaded videos of them using the card to make purchases so apparently they work, but the only way to know for yourself is to invest, receive the card and start using it. So if anyone has gotten a card and used it, please share your experiences below. Thanks and happy investing!