Airsoft Zeel shows two products in 1 package, the WE M4 RIS Gas Blowback Rifle with a Bifrost Smoke Tracer unit mounted. The WE M4 RIS GBB Rifle Black is a gas blowback airsoft rifle that fires in semi-automatic and full-automatic modes. It's designed to look like a modern assault rifle and has a metal RIS handguard for attaching tactical accessories. The SPIT FIRE/SMOKE/BI-FROST/TRACER Silencer Version 2, which is 175mm long, 42mm wide, and has a battery life of 4 hours with low battery notification.