Here is the video fo the PTS Enhanced Pistol Shockplates for Tokyo Marui 1911 and Glock airsoft pistols that should be available now at retailers and dealers. These are specifically designed to reduce shock to the magazine if dropped, helping prolong the life of the magazine. The simple one-piece design made from TPU rubber has just the right hardness to absorb shock whilst being hard enough to avoid tearing if forced or pulled.
Booligan Airsoft does a megatest with the PTS Enhanced Polymer Magazine (EPM) to see if it can fit the rifles that accept M4-style mags in his collection... "Sometimes, you just need to pull out all of your guns and test out a magazine. Today is one of those times! PTS popped over one of their new EPM mags, so I figured the rational thing to do was to get out every gun in my collection that will fit it and put some rounds through it!"'