Wtfskins.com is a known, global platform on which, like many hundreds of other people, you can bet and win virtual weapon skins in Counter Strike: Global Offensive. Additionally, the site, except to traditional exchanges of a specific amount of currency for CS: GO skins, also offers the possibility of buying many other various items such as skins for the known game Dota 2 or H1Z1. 

To activate Your code:
-Go to wtfskins.com
-Sign in through steam at the top right
-Press deposit
-Select the option to use a gift code
-Enter your gift code and enjoy your gems!