Lightweight, comfortable helmet mounted earmuff that deliver a high attenuation level performance to address the most difficult noise situation . These slotted earmuffs can be use with a wide range of safety helmets . Earmuff cups should snap in place during use & swing back when not in use Can be perfectly fitted with Safety Helmet, Helmet Visor Carrier BGVH with series FC48 or Series SV-1 visors to provide complete head, face and hearing protection . SNR : 27dB Comply to EN352-3 Packing : 1pr/box 24prs/carton