M35 Green Neoprene for added chemical resistance Listed mainly by trade-size, available in solid, one-hole, and two hole rubber stoppers. Uses vary widely, some are outlined below: Carboy Stoppers Crucible Holders Laboratory & Test Tube Stoppers Masking Applications Micro Stoppers Pipe…

Size No. 000, 00 and 0 have hole 3 mm diameter; sizes No. 1 and 2 have hole 4 mm in diameter; all other sizes have hole 5 mm in diameter.