X-GRIP S&W M&P Compact 9MM/40S&W Magazine Spacer Black. 355 Caliber Magazine Capacity: 5 Round Gun Model: Smith & Wesson M&P 40 Smith & Wesson M&P 9 Package Contents: X-GRIP S&W M&P Compact 9MM/40S&W Magazine Spacer What firearm models does the manufacturer say X-GRIP S&W M&P Compact 9MM/40S&W Magazine Spacer is compatible with? The manufacturer suggests that X-GRIP S&W M&P Compact 9MM/40S&W Magazine Spacer is compatible with Smith & Wesson M&P 9 Smith & Wesson M&P 40X-GRIP XGSWMP: S&W M&P Compact 9MM/40S&W Magazine Spacer Black