The Valken SMG airsoft magazine is constructed of durable hard polymer material, are lightweight, and can take a beating. This 6mm AEG magazine features a long 45 SMG design and fits the Valken ASL+ Kilo45 AEG or ASL+ Sierra AEG. This AEG magazine also comes with a high quality spring and clutch system to ensure smooth feeding. We recommend our Valken SMG adapter so you can use these airsoft magazines with any M4/M16 airsoft electric rifle.