Glock is introducing two new Gen4 models, the G17B and G19B. The B stands for beginner. Features are: 1. they will run on cheap, bargain substandard ammo 2. 10# dual recoil spring assembly 3. Added rail and grip training weights Frames will be light blue to easily distinguish them from service pistols. Warning: Use of full power service ammo will void the warranty.Not to be used for personal defense. Have a nice day.