VDO bike computer The M Zero WR807 is an easy-to-use entry-level model among bike computers. The bike computer has various mileage functions, a speed function and a time function. These are clearly displayed on the display. The handy thing about this model is that it can be operated with one button. Specifications: Color: black, red Gender: unisex Material: plastic Dimensions: 4 x 3.8 x 2.3 cm (L x W x H) Weight: 50 grams Wheel size: 16 to 29 inches Power supply: 1 x CR123A battery (included) Functions: Daily distance Total number of kilometers Wheel kilometers Current speed Running time