Fit plain end culture tubes and flasks with DeLong style necks or ports
Molded from durable, autoclavable polypropylene (PP)
Ridges inside cap provide secure grip and gas exchange
Available in five (5) colors for easy sample identification and organization
Maintain sterility without cotton plugging
Reduce sample evaporation compared to cotton plugging
Provide same evaporation and sterility benefits as stainless steel closures