3M Skull Screws Probed Test Plugs are equipped with a probe tube for fit testing using the 3M E-A-Rfit validation system. These earplugs cannot be used for hearing protection.

• The NRR may overestimate the hearing protection provided during typical use
• 3M Skull Screws Probed Test Plugs are a specially probed version of the standard plug
• Used in fit testing
• Allows you to conduct an earplug fit test for the P1300 and P1301 earplugs