Varia RearVue 820 features Garmin's most powerful and precise radar yet giving you more reliable alerts than ever before. The taillight offers up to 1.24 miles (2 km) of visibility and has a brake light that shows when you're slowing or stopping. Varia RearVue 820 radar detects vehicles approaching from more than 190 yards away with a wider field of view. A sleek compact design and new seatpost mount means Varia RearVue 820 fits cleanly onto almost any road or gravel bicycle.Run times: Up to 24 hours in daylight flash mode up to 10 hours on steadyDaylight visibility lets approaching vehicles see you from up to a mile awayMultiple display options. Pair it with your compatible Garmin device your phone or bothThe Varia app has you covered if you're using your phone as a primary or backup displayLumens: 25 solid 8 peloton 40 night flash 100 day flashCompatible with the Varia seat rail mount kit (sold separately)