3M 93713, Skull Screws Probed Test Plugs 393-2012-50, 50 pair/case, 10 pair/bag, 5 bags/case, 7000128264

3M Skull Screws Probed Test Plugs are a specially probed version of the standard plug. This product works with the E A Rfit Validation System and allows you to conduct an earplug fit test for the P1300 and P1301 earplugs.