https://buy.garmin.com/en-GB/GB/p/698001 https://buy.garmin.com/en-GB/GB/p/698001 Basically you connect it to your bike computer and it puts a little line alon

https://buy.garmin.com/en-GB/GB/p/698001 https://buy.garmin.com/en-GB/GB/p/698001 Basically you connect it to your bike computer and it puts a little line along the side, cars appear as dots on the line and move along it as they get closer to you and your computer emits audible beeps when it detects a car. Has a different, more urgent beep when it detects a large vehicle like a lorry or a bus, or if a vehicle is travelling at a high speed relative to you. Highly recommend it, haven't had any false negatives (obviously I still look over my shoulder, it's just nice to know a car's coming from a distance away and if they're going very fast).