3M 7000009668 earmuff is a hard hat attached hearing protection device. With an attenuation rating of 24.0 decibels, it effectively reduces noise levels. The earmuffs are shaped for a comfortable fit and are not metal detectable. They have a CSA Class AL certification and are not electrically insulated or dielectric. These cordless earmuffs are not moisture resistant but are designed for cap-mount use. They do not have Bluetooth capabilities but are compatible with noise attenuating headsets. Overall, these durable earmuffs provide reliable hearing protection on the job site.