Can be combined with all FAST helmets, ACH helmets and MICH helmets as long as they have side bow railsTests have shown that Comtac I and Comtac II headsets can be perfectly combined with this headset adapterWhen hanging after the Comtac intercom headset, the headset is pulled out of the arched headband that is used on the card directly on the hanging chainThe hang loop can be attached to the helmet on the 2 sides of the helmet rails, after installation the Comtac headphones headset can rotate freelyRequire some assembly by mainly removing the earmuffs from the headband and then snapping them onto the adapterscolour:BlackMaterial:Nylon + metalsize:10 x 5cmPackage Contents:2 x headphone rails1 x wrenchOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.