Certification : ISO 9001 Name:rubber stopper, rubber plug Material :EPDM, NR, IIR,MVQ,FPM,CR,ect Small Order Accepted Black # 0 stoppers. These are domestically manufactured lab grade stoppers. The stoppers are solid, natural rubber. The size of each stopper is molded on the top. Specifications: Size # 00Diameter Top:17mmDiameter Bottom:13mmHeight: 25mmDurometer: 50 +/- 5Free Sulphur: 0.05%Net ...