Durable full metal frame construction Compatible with Echo1 ASC-H and VFC MK17 Hi-Cap magazine is able to fit up to 500 rounds Uses a winding wheel that provides tension to consistently feed BBs Large capacity is useful for airsoft support roles and gunner loadouts In the Box 1X Magazine Specifications: Brand Echo1 Build Metal Frame/Polymer Internals Magazine Capacity 500 Rounds Compatibility Echo1 ASC-H AEG, DBoys & VFC MK17 AEGs Color BLACK California Proposition 65 Warning: Cancer and Reproductive Harm - www.P65Warnings.ca.gov