You deposit your skins on to the site and choose a multiplier / custom item to upgrade your skin to. Higher the multiplier, lower are your chances of success!

DATDROP – CASE OPENNING | UPGRADER | FREE BONUS CODE

Most reliable CS:GO Case Opening Website with top skins and high profit. Craft better skins fast and easy every day!
https://datdrop.com/
BONUS CODE:
BETS

WTFSKINS – ROULETTE | CRASH | UPGRADER | FREE BONUS CODE

Enter as many items as you want to upgrade into the cube at the top. From there you can select what multiplier you want to roll for. If you win the roll then you lose your item and you receive the item you were trying to get. If you lose the roll then you lose your item and do not receive anything.
https://www.wtfskins.com/
BONUS CODE:
BET

GAMDOM – ROULETTE | CRASH | UPGRADER | HI-LO | FREE BONUS CODE

Gamdom is the best and reliable service to upgrade your skins in the crash game, fun , fast and easy to use! Come and win more skins.
Discover a better way to upgrade skins. Instantly deposit skins, and watch them grow. Cashout anytime.
https://gamdom.com/
BONUS CODE:
CSGOBET

HELLCASE – MULTI CASE OPENING | CASE BATTLE | UPGRADER | FREE BONUS CODE

Hellcase is the best place to open CS:GO cases and get the best drop.
Now you don’t need keys for case opening, just use our service and get the best drop from cheap crates!
https://hellcase.com
BONUS CODE:
csgobonus