Rice Lake Weighing Systems RLWS Calibration / Test Weights Precision Calibration Weights Rice Lake Weighing Systems manufactures precision calibration weights, including all ASTM, OIML, and NBS classes, for balances and scales. We also provide special design weights, weight kits, and weight cases. Our precision weights are designed specifically to assist you with ISO 9000 traceability requirements. PRICE: Please see PDF Order Request