Accuris Instruments offers a range of precision calibration weights that are ideal for calibration of your Accuris lab balances. The Benchmark Scientific W1000-500 is the 500 gram weight and meets class F1 tolerance per OIML (International Organization of Legal Metrology) Recommendation R111. Made of highly polished, non-magnetic stainless steel, the W1000500 calibration weight comes in a protective plastic case.