Acetech Raider Tracer Unit w/ Bifrost Module (Black / Tan) Color:Black User can choose either one

User can choose either one of the combinations to be installed:

Depending on your HPA engine

Caliber: 6mm BBs

Aluminum Upper Receiver with Metal Barrel Assembly

Acetech Raider Tracer Unit w/ Bifrost Module (Black / Tan) Color:Black User can choose either oneAcetech Raider Tracer Unit with Bifrost M Tracer Unit (14mm CCW) Intelligent Power Control. Compatible with standard, green tracer BBs and Gel Balls. USB Type C Port for Charging. Bifrost simulates muzzle flash with multi color flame effect. The effect of flame depends on volume of gas or fog around the muzzle, more volume makes better effect. Designed for any Muzzle Thread 14mm CCW and 11mm CW. The contents of the package come with an M14 to M11+