Glock question

[tap&rack_TXinfidel]

I just got a hold of a Glock "factory" minus (3.5) connector but I want to be sure of its authenticity. How can I distiguish it from all the other 3.5 connectors out there?

 

[gladi8r]

Glocks connector will have a minus sign on it

 

[Jon Payne]

Also there won't be a "S" on the bottom