ASTM Class 1 Calibration Weights for calibration checks of laboratory balances are polished stainless steel and supplied with protective plastic case and glove for handling. 10kg and 20kg weights feature built-in recessed grip for easier handling. Sets of calibration weights are available in 1mg to 100g and 1g to 100g ranges. Models are available with NIST Traceable or NVLAP Certifications.