Optime 105 Helmet Ear Muffs - NRR 27 (For Petzl helmet)Part: ARB SAF205 3M PELTOR Optime 105 Earmuff is a high-performance hearing protector. Recommended for high noise exposure situations (like running a chainsaw, chipper, or stump grinder.) Dual-cup design and soft, foam-filled cushions provide high attenuation and comfort. 27 decibel Noise Reduction Rating (NRR) Peltor helmet-mount ear muffs. Designed to be worn with any helmet with standard attachments. Compatible Arborist Helmets: Petzl Vertex Vent Petzl Vertex Petzl Alveo vent Petzl Alveo Kask Super Plasma Pacific Kevlar and any climbing helmet or hard hat with standard ear muff slots Features Dual cup protection Liquid sealing rings for improved comfort Unique low profile headband design helps maintain constant pressure Large space inside cup helps reduce moisture and heat build-up Soft wide cushions help reduce pressure around the ears and improve comfort Easy to replace cushions and inserts help keep ear muffs hygienic Easy to understand noise attenuation symbol to help ensure correct product selection Helmet mounted version fits directly to many safety helmets without the need for an adapter