Overview
This is a gas-powered magazine designed for use with RAVEN EU Series gas blowback (GBB) pistols (often the EU / G-Series pistols).
Compared with standard magazines, this version gives a much larger BB capacity — roughly 50 rounds — letting you stay “in the fight” longer before needing to reload.
Construction & Design
The body is made of metal (alloy), giving it durability and a realistic, heftier feel. 
It uses polymer feed lips and a polymer BB follower, plus a polymer base plate. 
The magazine has a matte black finish, typical of many airsoft EU-series magazines, and a double-stack design to accommodate the increased BB capacity. 
Functionality
The magazine is gas-powered. You refill it with standard “green gas” (or compatible airsoft gas) via a fill valve at the bottom of the magazine. 
BBs are loaded either from the top/front — by hand or more ideally using a speed loader — once the BB follower is pulled to the bottom. 
The base plate is removable, allowing for easier maintenance (cleaning, replacing worn parts, etc.).