Strike Industries Enhanced Magazine Plate for Glock 17/22 Magazines, +6 for 9MM and +5 for 40S&W, Black SI-EMP-G940
Specifications:

Caliber	9mm Luger/40 Smith & Wesson (S&W)
Capacity
Finish
Model	E.M.P
Material	Polymer
Type	Magazine Extension
Model Fit	Glock 9/40
Brand Fit	Glock
Max Capacity