[H] Hitman Sniper Challenge keys [W] offers

any of these?
http://www.steamtrades.com/trade/1Lcmz/hhotlinemiamiretrocitysquarepack25amazonpaypalotherswwalkingdeadmarkofninjaoffers

I don't think it's a real good bargain. Hitman sniper challenge is obtainable for free.
It's a gift or a key?

How can i activate it (i also have a key)