Black Rubber Stopper #15 Solid. Top diam. is 4.055"(103mm). Bottom diam. is 3.268"(83mm). Height is 1.535"(39mm).
Weight of each is approximately 12.5 ounces.
Forensics Lab Supply Number 3730126.
Formerly Grau-Hall Corporation dba Grau-Hall Scientific.
NOTE: Unlike some inexpensive imported products, these stoppers are made to standard size and hardness specifications.