Garmin Varia RearVue 820

Specs

Radar Range: Up to 140 yards (approximately 128m)

Vehicle Size Detection: Distinguishes cars, trucks, and large vehicles

Threat Level Detection: Assesses closing speed to prioritize alerts

Brake Light: Automatic activation on deceleration

Compatible: Garmin Edge computers, Garmin watches, Varia app

Connectivity: ANT+, Bluetooth

FAQ

What are vehicle size detection and threat level detection?: Vehicle size detection distinguishes between cars, trucks, and other large vehicles so your display can show you not just that something is approaching but what kind of vehicle it is. Threat level detection assesses how quickly a vehicle is closing the gap to prioritize which alerts need your attention first.

How does the automatic brake light feature work?: The brake light feature detects deceleration using the onboard accelerometer and automatically activates a brighter light pattern to alert approaching drivers that you are slowing. This is particularly useful on descents and when stopping at intersections.

How does the RearVue 820 compare to the RTL515?: The RearVue 820 adds vehicle size detection, threat level assessment, and automatic brake light over the RTL515. The RTL515 provides standard radar detection up to 140m with a tail light. Both pair with Garmin Edge computers, smartwatches, and the Varia app.

Best For

Road cyclists who want the most advanced rear awareness available and are upgrading from the RTL515 or buying their first Varia. Vehicle size detection, threat level assessment, and the automatic brake light make the RearVue 820 the most intelligent radar in the Varia lineup.