Class F test weights are primarily used to test commercial weighing devices by state and local weights and measures officials, device installers, device owners and service technicians. Class F Test Weights may be used to test most accuracy Class III scales, all scales of Class III L or IIII, and scales not marked with a Class designation. Class F weights are also acceptable for use in verifying scales that have 0.1% accuracy or lower. Cardinal Scale certifies that the weights listed below are calibrated to NIST 105-1 Class F Tolerances. Use these test weights to calibrate an inaccurate scale, or just to make sure your scale is performing as accurately as it should. Cardinal's calibration weights are available in 1, 5, 25, and 50 lb weights. The 25 and 50 lb test weights come with integral grip handles to ease transport.