Best price - Strike Industries MP 9mm/.40 Full Size 6 Round Extended Magazine Plate

This is the best price I could find for a bumper base plate that adds about 5 rounds. The spring doesn't seem to be any thicker or stronger than the SW OEM spring and it's only half a loop longer than the factory one. This fit and functioned on SW MP40 full size mag, SW MP9 full size mag, Ruger SR40 full size mag and Ruger SR9 full size mag. Plus 6 barely with 9mm and plus 5 with 40sw. Additionally I slapped this on a Walther PPQ M1 9mm full size mag. I did have to shave off a little more than 1/16 metal off the ledges on each side that hold the base plate but once I did that it fit just fine. With the Walther it only held plus 5 in 9mm. Overall it looked ok on the SW, looked bad on the Ruger and looked best on the Walther. I will be buying more of these. The description says steel but the only steel in this is a half inch by half inch plate that prevents the bumper base from sliding off.