Made of polyethylene
Plug type push-in caps and 2-position snap caps are made of polyethylene for test tubes with outside diameters of 12 or 17 mm. Dual position caps offer two possibilities: the closed but unsealed position where samples are maintained aerobic for microbiological procedures; and the fully sealed position where the cap is pushed tight to seal the tube for anaerobic use or for storage, transfer and centrifuge applications.