The WE 40rnd Magazine is a full-metal spare magazine designed specifically for WE-Tech’s series of Gas Blowback (GBB) submachine guns, including the SMG-8 and the SMG-7 (also known as the "Small Rice 7" or "NP7").
 
Key Specifications
Capacity: Standard capacity is 40 rounds, though some retailers list it as holding up to 44 BBs.
Compatibility:
Compatible with: WE SMG-8, WE SMG-7 (Small Rice 7 / NP7 / WE SMG-A1).
NOT Compatible with: Umarex (VFC/KWA) MP7 or Tokyo Marui MP7/SMG-7 platforms.
Construction: Heavy-duty aluminum alloy body with polymer feed lips and a steel spring.
Gas Source: Optimized for Green Gas, but also compatible with Red Gas and Propane.
Weight: Approximately 450g to 530g.