Sealed electrolytic cell( CS935S) is the sealed cell, the sealing screws & O-rings ensure the sealing. This cell provides a complete sealing environment for the experiment. The lid can be rotated to open. The holes on the Teflon lid are tailored according to requirement. You just tell us which electrodes will be inserted or the OD of the electrodes to be inserted. Volume: 50/100/150/250ml optional