Cycling · Head-to-head
Garmin Varia RearVue 820 vs Magicshine SEEMEE R300
Which should you buy? Our verdict on both, pulled from our full The Best Bike Radars: 4 Compared (and One to Skip) comparison.
The RearVue 820 has the widest beam, the richest alerts and the longest day-flash runtime of the four. The SEEMEE R300 gives you most of the core function, radar alerts on a head unit or phone plus a bright day flash, at a budget price.
Garmin Varia RearVue 820
Buy itGarmin's newest radar tail light, with a 60 degree beam, vehicle size and lane-change alerts, a brake light and the longest day-flash runtime here.
- Garmin lists a 175 meter detection range and a 60 degree beam, wider than the 35 to 40 degree beams quoted elsewhere in this group.
- Threat classification uses speed, vehicle size and lateral range, so a compatible Edge computer or the Varia app can show small, medium or large vehicles and lane changes.
- Battery life is listed as 24 hours in day flash, 15 in peloton, 10 in solid or night flash and 30 in radar-only mode.
- It is the most expensive radar in this comparison.
- Its brightest mode is 100 lumens in day flash, the same peak that Magicshine lists for a budget price.
- The size and lane-change alerts need the latest compatible Edge computers or the Varia app, so older head units may only show basic alerts.
Magicshine SEEMEE R300
Buy itA budget radar light with a 140 meter range, ANT+ alerts on the main bike computer brands, phone alerts in its own app and a full runtime table.
- Magicshine says it works with Garmin, Wahoo and Hammerhead computers over ANT+, and its app gives real-time rearview alerts over Bluetooth.
- It publishes runtimes for every mode with radar on and off, including 16 h 12 min in day flash and 26 h 18 min in radar-only mode.
- The 2-year warranty is twice the 1-year cover that Wahoo and Bryton list.
- The 300 lumen headline does not appear in the mode table, where the brightest mode is a 100 lumen day flash.
- The 100 hour runtime claim is for a 0/3/3/10 lumen eco flash with the radar switched off.
- At 113 g it is the heaviest unit here, and the IPX6 rating is one step below the IPX7 of the other three.
Side by side
The 8 criteria below are the ones our full comparison judged every product on, narrowed to these two.
| Garmin Varia RearVue 820 Our pick | Magicshine SEEMEE R300 | |
|---|---|---|
| Our verdict | Buy | Buy |
| Best for | Riders who want the most complete radar package and already use, or plan to use, a Garmin Edge, Garmin watch or the Varia app. | Riders who want working radar alerts on a head unit or phone without paying flagship money. |
| Price tier | $$$ · premium | $ · budget |
| Stated detection range | 175 m | 140 m |
| Radar beam width | 60° | 35° horizontal, 45° vertical |
| Brightest listed mode | 100 lm day flash | 100 lm day flash (300 lm headline) |
| Day-flash runtime | 24 h | 16 h 12 min with radar on |
| Radar-only mode | Yes, 30 h | Yes, 26 h 18 min |
| Alerts on a phone while riding | Yes, Varia app | Yes, Magicshine app |
| Brake light | Yes | Not listed |
| Weight and water rating | 90 g, IPX7 | 113 g, IPX6 |
Which one is right for you?
Pick the Garmin Varia RearVue 820 if
riders who want the most complete radar package and already use, or plan to use, a Garmin Edge, Garmin watch or the Varia app.
Know before buying: it is the most expensive radar in this comparison.
Pick the Magicshine SEEMEE R300 if
riders who want working radar alerts on a head unit or phone without paying flagship money.
Know before buying: the 300 lumen headline does not appear in the mode table, where the brightest mode is a 100 lumen day flash.
The bottom line
Our overall pick is the Garmin Varia RearVue 820 - Garmin's newest radar tail light, with a 60 degree beam, vehicle size and lane-change alerts, a brake light and the longest day-flash runtime here. Choose the Magicshine SEEMEE R300 instead if riders who want working radar alerts on a head unit or phone without paying flagship money.
Want the full picture, including the other options we compared and the popular one we'd skip? Read the complete The Best Bike Radars: 4 Compared (and One to Skip).