Pure, non-sintered PTFE Lab-Thread Tape contains no adhesive, yet does a superior job of sealing small apertures. Conforming to irregularity of surfaces, threads and joints of all types, Lab-Thread Tape eliminates the need for lubricants and vacuum greases. PTFE Lab-Thread Tape can be used on ground glass joints, desiccators, bell jars, freeze-drying equipment, etc. A wrap of Lab-Thread tape provides a vacuum tight seal that will release even after long periods. "Freezing" is totally eliminated. 12.7mm (1/2") wide x 7.6 meters (300") roll.