Peltor Next Skull Screws No-Roll Foam Ear Plugs (NRR 30) (Box of 120 Pairs)WilliamMay 30, 2012A co-worker gave me a pair of Skull Screw ear plugs when I complained that I had tried, what I thought was every plug on the market. I have never been able to wear ear plugs for more than 2-3 hours at a time. I comfortably wore the Skull Screws on my next shift for 8 hours even forgetting about them into lunch. Even though the plugs can be used over many times, I ordered a box of 120 that afternoon. Also remember you can take them off of your taxes for work related items.