Bicycle Speedometer and Odometer Wireless Waterproof Cycle Bike Computer with LCD Display & Multi-Functions by YS (YS-589)

Installation was quick and easy. There were helpful diagrams included in the instructions booklet that made it clear where each piece of the apparatus was to be installed. Directions were concise and easy to follow. Important specifications were emphasized to ensure proper installation. Also included was a helpful chart for calibrating the unit based on wheel diameter.I paced my fiance's car going 8mph while I rode the bike. The speedometer matched the speed of the car and seems to be accurate. The function of each key and combination of keys on the unit was clearly outlined. I only needed to reference the outline once to figure out how to manually power it down, everything else was intuitive.Overall, I am satisfied with the purchase. This is an inexpensive speedometer that works as expected.

The instructions weren't that bad, it does take a little intuition though. The unit works during the day, however won't operate at night when I commute home. The company sent me a new one, that did the same thing. I ride with a bike mechanic, he is clueless why both units won't operate at night. I'm going to have to buy one from the bike shop and toss these out.