This is Advanced AEG Mag Spring. Was created for aims, when you used mag for a long time and base spring doesn't works properly, or just you bought cheap mag and they won't works normally.
Made from Unique Steel Alloy. Provide more than 1000 cycles of charging / discharging of AEG Mag (base mags usually provide 50-100 cycles). Doesn't rust.
Works with ANY AEG MAGS! MP-5, M4, G36, MP-7, AK, doesn't matter what do you have. And works with ALL Companies, who making AEG Mags. Cyma, MAG, GP, GG and etc.
Material: Unique Alloy of Steel.