Features and Benefits: * This easy to use and read tool allows for accurate belt tension to be set after belt replacement, adjustment, or wheel service * Use on secondary drive belts with a 10 lb. spec. Instructions: 1. Position the small O-ring over the 10 lb. mark. 2. Position the U-shaped belt cradle against the bottom of the belt at a 90 degree angle and locate the large O-ring to a reference point, record reading. 3. Push upward on the rubber bumper until the small O-ring touches the bottom of the tool body. Re-align the large O-ring to the reference point, difference in the reading is the belt deflection (refer to service manual for spec.).