With cap with S40 screw thread and srewable frit made of PTFE. Approx. pore size 3 µm for optimal formation of gas bubbles into the liquid. Because all parts are made of high-quality fluorocarbon resins, a broad range of applications are possible. The threaded inlet and outlet connections accept 4 x 6mm i.d. x o.d. tubing , (1000 ml version: 5 x 8mm i.d. x o.d. tubing).