3M PELTOR Earmuffs X4/ X5 Probed Test Cushions easily snap into the 3M PELTOR X-Series X4 and X5 Earmuffs (sold separately) to allow for fit testing with the 3M E-A-Rfit  Dual-Ear Validation System. The complete system issues a pass or fail rating based on the employee's personal attenuation rating (PAR) when wearing 3M PELTOR X-Series X4 and X5 Earmuffs3M PELTOR Earmuffs X4/ X5 Probed Test Cushions work with the PELTOR X Series X4 and X5 earmuffs (sold separately)  to allow for fit testing with the 3M E A Rfit  Dual Ear Validation System. These cushions are used specifically with the 3M PELTOR X Series X4 and X5 Earmuffs to help employers determine the level of protection the earmuffs are providing. Adapter clips hold microphones next to earmuffs for proper positioning during testing. Case includes two pair of probed cushions and two pair of adapter clips. Workers can bring the 3M PELTOR X Series Earmuffs they are using in the workplace, have the operator remove and inspect their cushions, replace them with the appropriate probed test cushions, and be fit tested.