The band you select should be the smallest one that stretches across the crank arm.
2. On the non-drive side, place and hold the flat side of the cadence sensor on the inside of the crank arm.
3. Pull the bands around the crank arm, and attach them to the hooks on the sensor.
4. Rotate the crank arm to check for clearance.
The sensor and bands should not contact any part of your bike or shoe.