Cork Stopper, 10-Pack Biology_Cell Biology Stopcock with standard ground joints

Stopcock with standard ground joints features 19/26 socket size in borosilicate 3

stored in a wooden block for suspension from spring balances and pulleys in physics labs

Hexagonal hollow stopper in borosilicate glass features 29/32 cone with round end for sealing ground joint vessels and chemistry apparatus

especially in procedures involving DNA

Entry-level two-part human skull model separates the skull cap to reveal the cranial cavity for introductory head-anatomy teaching at secondary and college levels

Cork Stopper, 10-Pack Biology_Cell Biology Stopcock with standard ground jointsNatural cork bark stoppers with a tapered profile seat into a range of bottle necks and flasks for general purpose non reactive closure.