Peltor Skull Screwsâ„ Uncorded Safety Ear Plugs Sold As: 120 Pair/Box These edgy earplugs have been designed to bring a radical new attitude to the workplace and help boost compliance. It's a different plug - that's going to make a difference. Grab young workers by the ears with Metallic-Look Foam, Screw Grip and Twist-to-Seal Design. And knock noise to its knees with a decibel crushing NRR of 30 dB. Skull Screws. Features: * Easy grip for clean insertions * Look of soft metal, feel of foam * Screwing or twisting the plug while pushing it into the ear canal can help achieve the proper fit * Tough Protection: NRR 30dB