Bluetooth Bicycle Speaker Zealot S1 4000mAh Power Bank Waterproof Speakers with Full Outdoor Accessories(Bike Mount, Carabiner...)(Red) BEST BICYCLE SPEAKER: It's a super transformers for you: music playback (Bluetooth, AUX, TF card supported)and hands free call, torch light, external battery/power bank. STUNNING & STRONG SOUND:Built-in 40mm drivver, Neodymium stereo amplifier presents you live experience in talking and surprising, excellent sound. LONG BATTERY LIFE: 4000mah rechargeable battery provides a long time usage (up to 24hs by TF card play) and turns it into a backup power supply as well. FULL-EQUIPPED OUTDOOR ACCESSORIES: ZEALOT considerately offer all you need when cycling with S1 - Bike mount & Carabiner & Audio Cable & USB Charging Cable & Silicone protective sleeve to ensure waterproof, dust proof and shockproof TIPS & WARNING: 1, To receive stronger FM signal, please be advised to plug charging cable into the micro USB port or plug in the AUX cable as a radio antenna. 2, The USB port is output for backup power supply, to juice up your phone or other devices, DO NOT insert U-disk into speaker