EasyFit MagWell for S&W M&P pistols in 9mm and .40 S&W cal. pistols Features:
Improves reloading speed by 50%
Increases magazine well opening by 49%
Protects magazine well of firearm  
Specification:   Fits Smith & Wesson M&P Pistols in 9mm and 40S&W cal. with medium and small size backstrap. (Does not fit M&P Compact; need to remove bottom edge of large backstrap for proper fit).   Made of polymer (nylon) material, durable and long lasting   Weight - 0.27 OZ (7.7 gram)
original frame tool - 0.16 OZ (4.6 gram)
weight added - 0.11 OZ (3.1 gram)

Maximum width - 1.47¨ (37.3mm)
Inside width - 1.42¨(36.1mm) - increased by 49%
Original inside width of S&W M&P magwell -0.95¨ (24.1mm)   Installation:
Note: If you are not comfortable with the installation, please have a qualified gunsmith to do the job for you.
1. Make sure the firearm is unloaded.
2. Remove the magazine from the gun handle.
3. Rotate the 'Frame Tool' 1/4 turn (90 degree) and pull it out (it is very tight fit). - picture A
4. Insert the 'Frame Insert' to replace the 'Frame Tool'. - picture B
5. Place the U shape magwell onto the 'Frame Insert' and screw tight. - picture C
6. Insert an empty magazine for fit testing.
7. Live fire at an approved area to get use with this new fixture.