Rubber Stopper, #11-1/2, Two Holes, Black, pack/3

Rubber Stopper, #11-1/2, Two Holes, Black. Similar to CG-3026 and CG-3027 except with two holes. These stoppers are suitable for practically all general laboratory uses. Composition ensures resiliency and pliability over a long period and withstands laboratory conditions without hardening. The dimensions are in accordance with specifications established by the N.B.S. and are low in free sulfur (1/2%). Autoclavable at 250 degrees F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Made in the United States.