Echo J7 Cycle Computer Manual -

: The spoke magnet must pass within 1–3mm of the fork sensor to register speed correctly .

However, based on common features of the Echo J7 (and similar units like the J6, J8, or other basic cyclocomputers), here is a that you would normally find in its manual. echo j7 cycle computer manual

Press the (or the small "Set" button on the back) to confirm and move to the next digit. : The spoke magnet must pass within 1–3mm

The is a popular wired cycle computer for casual cyclists and commuters who need basic metrics: speed, distance, trip time, and odometer. However, the original printed manual is small and easy to misplace. or other basic cyclocomputers)