Tippmann M4 Carbine Airsoft Gas Blowback meet up only Hollywood sports , tac city , project N1 / HPA Rifle Aluminum alloy receiver, barrel assembly and buffer tube mater with durable reinforced polymer furniture Designed to function with HPA or CO2 (mag sold separately) providing realistic recoil Adjustable rate of fire (8-15 RPS) and adjustable FPS (300-400 FPS) allow for customization for any field scenario Newly designed hop-up system; Accepts standard AEG type inner barrels and can use most standard AEG magazines when in remote line configuration Ultra lightweight polymer M-LOK handguard Can accept real AR spec stocks and handguards Remote line adapter included Made in the USA