Roy Rubber Stopper Set,1 to 6 Sizes Both Single Hole and Double Hole Lab Stoppers for Laboratory Flask, 36 Packs (White)

Description

The variety in sizes makes them useful in most size flasks.36 packs, 1 to 6 sizes,1#-3# each size have 6 packs include 3 holeless and 3 single hole.4#-6# each size have 6 packs include 2 holeless，2 single hole and 2 double hole..Meet your different need. High quality rubber material with good chemical stability and hot stability.