Tec-22 Scorpion 10/22 mag

[twinhairdryers]

So i've had an Intratec Tec-22 scorpion for years now. Tried all sorts of Ruger aftermarket 10/22 mags with it and only the RamLine black 25 rounder really feeds flawlessly in this gun. It has a little plastic slider piece on a spring on the back of it, seems like a sort of quick release lever or something. anyone know what this is, or where to get these types of Ram-Line magazines with the levers on them? can't seem to find them anywhere.