A Teflon cap with holes for electrodes.
This is a cell top for the ItalSens glass cell. The holes in the top allow a convenient placement of electrodes. Two holes are 6.5 mm diameter, one hole is 5.8 mm diameter, the two purge tube holes are 2 mm diameter. The overall outer diameter is 29.4 mm, the reduced outer diameter is 21 mm, the height is 20 mm.