Black Rubber Stopper #000 1-hole (3mm). Top diam. is .472"(12mm). Bottom diam. is .354"(9mm). Height is .709"(18mm).
Approximately 198+ per pound.
Forensics Lab Supply Number 3731101.
Formerly Grau-Hall Corporation dba Grau-Hall Scientific.
NOTE: Unlike some inexpensive imported products, these stoppers are made to standard size and hardness specifications.