The DeWalt DPG17 earmuff protects your hearing while offering Bluetooth wireless technology for streaming and phone calls. High-Fidelity speakers provide premium sound in this USB rechargeable item. NRR 25. Bluetooth Wireless Technology®. High Fidelity Speakers. Rechargeable Lithium Ion Battery. Micro-USB Connector Cable Included. Integrated Mic for Phone Calls. Adjustable Headband.