Design with small size and modern fashion look. built in boost circuit with loud sound reached 100-120 db

With rechargeable 280 mAh lithium battery, used more convenience .USB cable charge 1.2 hours full charge.

Contains USB cable,1.2 hours full charge.one charge have 2000 times ring bell can work about 20-30 days

Have 4 sound modes, whistle sounds, horn sounds, alarm sounds, tram sounds, dust resist, IP 65 waterproof level

Easy to install: put the silicone strap fixed on the handle. Suit for 0.86"-1.25"(22.2-31.8 mm )diameter bicycle handlebar