BV Bicycle Light Set Super Bright 5 LED Headlight, 3 LED Taillight, Quick-Release Up to 80 hours, visible to motorists over 1500 feet away, 4 x AAA, 2 x AAA (Best with Polaroid AAA Batteries) 5 LED headlight, tool-less handlebar mount, 30-40 feet range, quick-release mount, 4.1" x 1.3" x 1.3" 3 LED taillight, angle adjustable quick-release mount. 3 modes on each light Weather resistant. Fits most handlebars and seat posts (rubber sizing shims included) Please refer user manual attached below for instructions and troubleshooting steps.