Peltor ARC adaptors, left and right side attachment kit
Amazon.com : DLP Tactical Helmet ARC Rail Adaptor Set Compatible with Peltor ComTac Headsets (Black) : Sports & Outdoors
3M Peltor ARC Adapters, Left & Right Side Attachment Kit - MOD Armory
Comtac I & II ARC Adapter - Tactical Helmet Accessories Rail Suspension Mount Version for Airsoft Activities Ear Protection - Hearing Protection for Peltor Comtac Tactical Headset Airsoft Headset Black