With a compression cap and Viton O-ring to form a vacuum tight seal.

To use it as a syringe port, simply replace the O-ring with Teflon-lined septum. Cap accommodates 5.0 -7.5mm OD thermometer.

Replace Accessories:      

Viton O-ring, Size010:      3001-010    

Nylon Cap:                       3002-009        

Teflon-Lined Silicone Rubber Septum  13mm:     3003-1413