Garmin is offering their innovative rear facing bike radar system as a standalone unit. In other words, the Varia RVR315 does not have a light, nor does it come with a head unit or Garmin's RDU remote viewing unit. The seatpost mounted unit itself is lighter weight and compact. Garmin'a Varia app can be used with a smartphone as your remote viewer, and the simple app is very popular, using sharp and easy graphics, plus tone and vibration alerts to choose from that indicate the position and speed of rear-approaching vehicles.

The quality and effectiveness of the app is one reason people love this radar-only option. The other reasons are just as practical. Many people have invested in high quality bike lights so spending more money on a unit with a light may not seem like the best value to those folks. The vast majority of cyclists that use a high quality GPS head unit like the Garmin Edge series love the easy integration, and as the unit has ANT+ and BLE connectivity, other head units with ANT+ enabled Radar control are also easy to use. Companies like Stages, Wahoo, Hammerhead and Sigma offer models with this capability. The Varia radar has other great features, like integration with your favorite apps, such as Ride with GPS, to overlay your maps with rearview radar alerts.

The radar itself offers vehicle position and speed for vehicles approaching from behind up to 153 yards (140 meters) away, with a 40 degree coverage angle, which means it can detect even after leaving a corner. The unit mounts to virtually any seatpost via a universal mounting system. Garmin uses the same secure, proven quarter-turn mount system used on Edge head units. The compact size of the RVR315 means the chance of you hitting it with your leg is minimal, and it make it easier to mount under or above a seatpost mounted light and saddle bag.

The run time with the fully charged, integrated Li-Ion battery is 7 hours. It is USB rechargeable, and a cord is supplied. At just 51 grams, and carrying an IPX7 water resistance rating, the RVR315 is perfect for cyclists from racers to commuters, and offers very real and effective safety information to anyone who rides on the roads. Garmin is the world leader in personal radar devices, and for many cyclists, radar has delivered a greater sense of security and peace of mind not only the riders, but also their families.