These units fit in the bottom rear cavity utilizing friction fit to secure it to the frame. Helps keep debris out of the magazine well. Pearce Grips specializes in designing and manufacturing innovative grips and magazine extensions right here in the USA. Pearce Grips products are sought after world wide because of their functionality and rugged dependability. Their product line includes the grips you need for virtually all modern firearms. In an age when things are mass produced over seas, it is nice to know that Pearce Grips products are manufactured in the USA.