Plentilab Cryo vials are manufactured from virgin polypropylene to ensure the highest quality & confirming to US FDA 21 CFR. These vials are free from heavy metals & inhibitory plasticizers. Easy to open & close, the unique grip screw cap provides a secure grip in wet condition. Inbuilt seal ring in the cap makes the vial totally leakproof. With prominent printed graduation and white writing area on the tube, these vials are suitable for temperatures ranging from -196° to +121° C.