Bluetooth Motorcycle Helmet Headset Speaker Wireless Motorbike Headphone w/Mic
BT17 Bluetooth-compatible 5.0+EDR Motor Hat Headset Waterproof Wireless Handsfree Earphones for Motorcycle Hat Intercom. Mic distance: ≤1m. Lithium battery: 3.7V/800mAh. For Shimano Altus Rear Derailleur RD-M310 7/8 Speed Bike Bicycle Cycle UK.