Earmor M11 ARC Helmet Rails Adapter Attachment Kit Fire & Rescue Bags Helmet liner is made of

Helmet liner is made of 3/4” thick energy absorbing polystyrene

should I get the SM/MD or LG/XL

The housing is made from glass-filled nylon polymer

a fully adjustable hook-and-loop rear strap

Earmor M11 ARC Helmet Rails Adapter Attachment Kit Fire & Rescue Bags Helmet liner is made ofAllow 4 weeks for delivery Replace headband of EARMOR M31 M32 or helmet rail kit of M31H M32H with M11 ARC helmet rails adapter attachment kit, allows attaching your EARMOR hearing protector directly to ARC helmet rails. Features Durable, lightweight Rotatable for stowing For ARC Helmet Rails (Ops Core FAST MT) Can match with full range of FAST helmets, ACH helmet, MICH helmet as long as they have ARC rails on side Compatible most of the headsets on