The RearVue 820 is a generational leap over the RTL515 in nearly every specification. The radar detects vehicles from 175 meters away (vs 140m on the RTL515) with a wider 60-degree field of view (vs 45 degrees). Battery life jumps to 24 hours in day flash mode (vs 16 hours). The tail light is brighter at 100 lumens day flash (vs 65 lumens) and visible from 2 km (vs 1.6 km). The 820 adds features the RTL515 doesn’t have at all: brake light detection, vehicle size classification (small/medium/large), threat level assessment, same-speed tracking, custom light patterns via the Varia app, radar-only mode, and USB-C charging. If you’re upgrading from the RTL515, the improvements are significant across the board.

No. The RearVue 820 is a radar and tail light only — it does not include a camera. If you want continuous ride recording with incident detection, the Varia RCT715 ($399.99) combines radar, tail light, and a 1080p camera in one unit. The trade-off is that the RCT715 uses older-generation radar (140m range, 45-degree field of view, no vehicle size detection or brake light) and has significantly shorter battery life (6 hours max vs 24 hours on the 820).

The RearVue 820 pairs via Bluetooth LE and ANT+ with compatible Garmin Edge cycling computers (Edge 540, 840, 1040, 1050, and others), select Garmin smartwatches (fēnix, Forerunner, Enduro, etc.), and the Varia smartphone app on iOS and Android. It also works with third-party apps like Ride with GPS, Hammerhead Karoo computers, and Wahoo Elemnt computers via ANT+. Advanced vehicle tracking features (size, threat level, lane position) require the latest compatible Edge computers or the Varia app.

The RearVue 820 detects when you’re slowing down or stopping using its built-in accelerometer, and automatically triggers a distinctive flashing pattern that alerts drivers and other cyclists behind you. This works in any light mode. It’s similar to a car’s brake light but for cycling — a first for the Varia lineup. The RTL515, RVR315, and RCT715 do not have this feature.

When paired with a compatible Edge cycling computer or the Varia app, the RearVue 820 classifies approaching vehicles as small, medium, or large. It also tracks their side-to-side lane position and assesses threat level based on speed and path of travel. This means you can see not just that a vehicle is approaching, but whether it’s a car or a truck, whether it’s changing lanes toward you, and how urgently you need to react. This is a RearVue 820 exclusive — no other Varia model offers this.

Yes. The RearVue 820 introduces a dedicated radar-only mode with no light output, lasting up to 30 hours on a single charge. This is useful if you already have a preferred tail light and want to add radar detection without replacing it, or for daytime rides where you don’t need the tail light. The RTL515 does not have a dedicated radar-only mode.

Varia RearVue 820 radar tail light, new seatpost mounting kit (fits most round, aero, and D-shaped seatposts), USB-C charging cable, and documentation. The Varia seat rail mount kit is sold separately for bikes where seatpost mounting isn’t possible.