GEN 5 Tactical Headset Military Hunting Shooting Noise Cancelling Headphones for FAST Helmet OPS Wendy M-LOK Arc Headset Item No.:HD-19 Product Name:Gen 5 Noise ReductionandSound Pickup Headset (With adapter) Product size: 22.5 x 13.2 x 10.5cm Product net weight: 0.515KG Product accessory: a headset body, a microphone, a pair of helmet connecting arms, a packaging bag, a pair of rail conversion pieces (please refer to the accessories picture for details) Product colour: black/green/mud Use instructions: This product needs to be used with PTT Suitable head circumference: Suitable for users with a head circumference of 52-62cm - - - - - - - - - - - - - - - - - - - - - - - - Item No.:HD-20 Product Name: Gen 5 Headset without Noise Reduction Function (With adapter) Product size: 22.5 x 13.2 x 10.5cm Product net weight: 0.515KG Product accessory: a headset body, a microphone, a pair of helmet connecting arms, a packaging bag, a pair of rail adapters (please browse the content below for details) Product colour: black/green/mud Use instructions: This product needs to be used with PTT Suitable head circumference: Suitable for users with a head circumference of 52-62cm Note: This version does not have the function of noise pickup and noise reduction, and the battery compartment and buttons are reserved for upgrading the noise reduction function. - - - - - - - - - - - - - - - - - - - - - - - - Item No.:HD-ACC-08 Product Name:helmet rail adapter for GEN 5 Tactical headset Product size: 10.5 x 13 x 4.5cm Product net weight: 0.15KG Product colour: BLACK/GREEN/TAN