Rice Lake Stainless Steel ASTM Class 2 Precision Metric Test Weight Kit, 20mg Mass Metric, ASTM Class 2 leaf-style weight with turned-up end to enable lifting, for use with microbalances or calibrating weights Stainless steel construction for stability, resistance to corrosion, and low magnetic susceptibility Meets American Society for Testing and Materials (ASTM) E617, Class 2 specification for use as a reference standard for calibrating high-precision top-loading balances with a readability as low as 0.01g to 0.001g Kit includes a precision test weight, handling glove, and protective case