The TSG-22 quickly and easily converts to any generation, even generation 4 of the Glock models 17/22/34/35/37 into an accurate .22LR pistol. Machined from a solid piece of heat treated 4140 steel, the TSG-22 maintains a similar weight and feel to your factory Glock allowing realistic shooting and training. A nitride surface treatment offers superb resistance to wear and surface friction. The barrel has a 1:16" twist and 1/2"x28 threads. It comes with factory Glock sights and includes a 10rd magazine.