Warne MESW54BLK Magazine Extension made of 6061-T6 Aluminum with Hardcoat Anodized Black Finish for S&W M&P Magazines (Adds 5rds 9mm Luger, 4rds 40 S&W)

These extensions feature an ergonomic shape that allows for better insertion, and finger grooves, allowing the magazine to be stripped from the handgun if needed.