TS TAC-SKY ARC Rail Helmet Mounting Hearing Protection Active Noise Cancellation Tactical Headset TSC2 Silicone Earmuffs+ U94 PTTDescription 1. The bracket rail adapter is the center rail of the ARC OPS helmet, which is suitable for most FAST series helmets, ACH series helmets and MICH helmets. 2. 360 free rotation, the rail bracket can be fixed on the helmet top rail and both sides of the helmet rail, the center telescopic rod can be adjusted freely. 3. The ear cups are made of silicone, which is more comfortable to wear and can bring better wearing experience compared with