Black Rubber Stopper #9-½ 1-hole (5mm). Top diam. is 1.811"(46mm). Bottom diam. is 1.496"(38mm). Height is .984"(25mm).
Approximately 9.96 per pound.
Forensics Lab Supply Number 3731217.
Formerly Grau-Hall Corporation dba Grau-Hall Scientific.
NOTE: Unlike some inexpensive imported products, these stoppers are made to standard size and hardness specifications.