My google-fu is not very good but I got some info from the certificate holder.....he won it at a GSSF match.
I pressed him for more info, and got the following:
The certificate is from Glock US, and entitles the holder to a free pistol. G17,G19,G26,G22,G23,G27,G31,G32 or G33 Gen 3 or Gen 4.
You can pay an additional charge and get different models. For example, $110 for a G20C or G21C or $107 for a G34/35 (long slide models).
The certificate IS transferrable, and must be sent to Glock USA from a dealer, with a copy of their FFL, and a check for the upcharge (if you go that route).
Takes about 8 weeks, and the pistol shows up at the dealer, and you pick it up.
I also learned that if you are a member of GSSF, even if you don't shoot their matches, once a year you get a certificate to buy a Glock at wholesale price.....worth the $30 per year if you ask me.....