Tippmann Arms M4 Mid Cap CO2 Magazine (Ten Pack) Airsoft Gun Cases & Backpacks these designs will also suffer T130007 these designs will also suffer from low closing forces that can drastically affect efficiency Full Pneumatic control over the Solenoid Timing & Bolt Ram Return (Synergistic with LPR) & other marker set points Purpose built for the Tippmann Arms M4 airsoft gun these magazines can take an absolute beating while proving to be reliable in every situation you might find yourself fighting through You bought arguably one of the newest powerhouse guns in terms of reliability might as well back it up with the purpose built magazines