Garmin Varia RearVue 820 Radar Light At the heart of the Varia RearVue 820 is Garmin’s most advanced cycling radar to date. It detects vehicles approaching from up to 175 metres behind, using a wider field of view for more reliable, earlier alerts. Whether you’re riding country lanes, busy commuter routes or fast descents, you’ll know what’s coming -; sooner and with greater accuracy. Bright Rear Light with Intelligent Brake Light Visibility saves lives, and the RearVue 820 delivers Garmin’s brightest rear light yet, visible from up to 2 km (1.24 miles) away. The built-in brake light automatically detects when you’re slowing or stopping and displays a distinctive flash pattern, helping drivers and riders behind you react faster. Advanced Vehicle Tracking and Threat Alerts When paired with a compatible Garmin Edge® bike computer or the Varia™ smartphone app, the RearVue 820 doesn’t just alert you to cars - it gives context. See whether approaching vehicles are small, medium or large, track lane changes, and understand threat levels based on speed, size and position. It’s next-level situational awareness for serious cyclists. Alerts Your Way - Visual, Audible and Haptic Stay informed without distraction. The Varia RearVue 820 connects seamlessly to the Varia app, Edge bike computers and Garmin smartwatches, giving you visual, audible and haptic alerts while you ride. Selected Garmin smartwatches can even provide voice alerts for approaching vehicles (available via the Garmin Public Beta programme), so you can keep your eyes on the road. Multiple Light Modes for Every Ride Adapt your visibility to the conditions with four light modes: Day flash Night flash Solid Peloton mode (designed to be easier on the eyes of riders behind you) You can also create custom light patterns in the Varia app, tailoring brightness and behaviour to your riding style. Compact, Clean and Easy to Fit With its sleek, compact design and new seatpost mount, the Garmin Varia RearVue 820 fits neatly onto almost any road or gravel bike. It’s also compatible with the Varia seat rail mount kit (sold separately), keeping your setup clean, secure and aerodynamic. Technical Specifications: Dimensions: 98.9 × 25.9 × 43.2 mm (3.9″ × 1″ × 1.7″) Weight: 90 g (3.2 oz) Light modes: Solid, Peloton, Night flash, Day flash Custom light mode configuration: Yes (with Varia Mobile App) Lumens: 25 (solid), 8 (peloton), 40 (night flash), 100 (day flash) Water rating: IPX7 Battery life: 10 hours (solid), 15 hours (peloton), 10 hours (night flash), 24 hours (day flash), 30 hours (radar-only) ANT+®: Yes (radar, bike lights) BLE: Yes (radar, bike lights) Viewing angle: 220° Visibility distance: 2 km Rear tail light - Brake light - Rear radar Lateral vehicle positioning Vehicle size classification Vehicle threat classification: Speed-, size-, and lateral-range-based Maximum vehicle detection range: 175 m Radar beam width: 60° Connectivity - Varia™ app compatibility In the Box: Varia™ RearVue 820 radar tail light Mounting kit Charging cable Documentation