Bicycle computer-bicycle odometer &speedometer, to set wheel circumference

bicycle odometer-YT-816
1.speed range:0~99.9m/km/h
2.large screen shows riding time, current speed,trip distance and rotations /m of the wheel,calorie consumption.
3.display current speed, freeze frame memory, set speed scale
4.high integration,stable function and save power.
5.with clock,scan, auto on and off swith
6.length unit options of kilometer/milen
7.wheel circumference'setting is available(60cm~239cm)
8.product dimensions:43.5*22.5*22.5cm