Super heavy-duty self healing injector ports. These heavy-duty red stoppers are the highest quality ports on the market. Autoclavable. These rubber self-healing ports can be used to make your own liquid culture jar lids. These extra heavy duty stoppers can withstand hundreds of injections before they will need to be replaced. They fit into a 1/2 inch diameter hole drilled with a 1/2 inch forstner drill bit.