the release is the allen thumb release
http://store.stringslinger.com/1539.html
i was just using one and i was pulling back my bow(my old crappy on, didnt get new one yet) and at about half draw it broke and the bow srting ripped the crap outta my face. it was only set at 50 LBS TOO!!!
not to mention i lost a arrow to boot
i will never buy anything made by Allen again