Work Tunes Mid February Durahide™ performance leather thumb reinforcement 41GB3Z Durahide™ performance leather thumb reinforcement 2 mm waterproof leather upper with sealed seamsRemovable comfortable PU insole90° heel angleOil resistant ultra lightweight PU outsoleDesign easing donning(Women: 2 sizes smaller) Width: WCSA Class 1 and ESR certified 3M Work Tunes Hearing protector with Bluetooth Noise reduction rating (NRR) of 24dB or higher when worn properlyEquipped with 40mm high fidelity Speakers for premium sound qualityEasy to use one button interface helps keep you focused on the jobBuilt in rechargeable batteryCharging cord includedVented headband design features removable padding for versatile comfortDurable design is great for everyday useAutomatic shut off helps extend the life of your batteriesVolume temporarily mutes when phone calls and messages are receivedHelps lower your risk of noise induced hearing lossNoise Reduction Rating (NRR) 24 dB*Requires 2 AA batteries (not included)Optional lithium rechargeable battery (sold separately) – 3M™ ALPHA1100 Rechargeable Li Ion Battery Pack for 3M™ WorkTunes™ Wireless Hearing Protector