ARC OPS-CORE HELMET RAIL ADAPTER FOR MSA SORDING HEADSET-DE Headphone helmet bracket contains tools,You need to modify it yourself to assemble not includehelmet ARC OPS-CORE HELMET RAILUSED Rail Adapter :can be used on full range of FAST helmets, ACH helmets, MICH helmets,etc who have ARC rails on side. The bracket can rotate 360 degrees and can swing up and down. Used to mount the headset adapter on the helmet. The operation is simple and easy to use. It is suitable for MSA SORDIN, TCI LIBERATOR II and other earphones. Hang your earphones on the helmet instead of on the headband, and then loosen the head, so that it is more comfortable to wear the earphones frequently and no longer be restricted. Note: The earphone holder does not include earphones and helmets