Backstrap sleeve slides down over the top of the magazine and fills the gap between the bottom of the grip frame and the base of the magazine. This sleeve only fits the #1 back-strap.
Specifications:

Caliber	45 Automatic Colt Pistol (ACP)
Capacity	N/A
Finish	Flat Dark Earth
Model
Material
Type	Spacer Sleeve
Model Fit	XD-S
Brand Fit	Springfield
Max Capacity	0