1. Battery model: 3 LR44 batteries 2. Give 6 batteries 3. Installation diameter: 19-36mm 4. Battery life: about 12 hours 5. Waterproofing IP55 level 6. Size: 9.5cm in diameter and 1.7cm in width 7. Installation: fix the wheel hub 8. Features: three flashing modes, slow flashing, quick flashing and constant flashing, are controlled by the switch on the edge of the product
