Review on JGRZF Bike Computer: Wireless Speedometer and Odometer with Backlight, Waterproof LCD Display – Ideal for Outdoor Cycling and Fitness (Wireless Computer) by Nick Winnett

Seems to be true. Although it took several attempts to enter the correct number for the distance to be accurate. I drove down the trail and measured 1 mile and 2 miles in my truck along the section that runs alongside the road. The number on the bicycle tire was 26 x 1.95. So I entered 2055. That was 0.090 per mile. So I tried measuring the tire as instructed and got 25.5 instead of 26. So I put 2024 in the computer. Still 0.045. From there I experimented on the track in a marked section I did in my truck. Went from 2000 to 1900 to 1800 and 1800 seemed to be the magic number. Exactly 1 mile from the distance I measured. Not that hard at all, it only took a few tries and I could have started over. I haven't tried other functions yet. Soon. I wanted to measure how far I travel. Apparently. Trails are marked almost every 1/4 mile. I know from experience that city parks aren't always accurate. Last minute changes to rates are possible, but no new markings will be made. There are inaccuracies due to the use of old vintage markings. Now I can drive the trails and see if the trail markers are accurate. In general, this is a good device for the money.