Black Rubber Stopper #0 1-hole (3mm). Top diam. is .669"(17mm). Bottom diam. is .512"(13mm). Height is .984"(25mm).
Approximately 73+ per pound.
Forensics Lab Supply Number 3731103.
Formerly Grau-Hall Corporation dba Grau-Hall Scientific.
NOTE: Unlike some inexpensive imported products, these stoppers are made to standard size and hardness specifications.