Cell Holder Shimzadzu constant temperature four-cell holder. Four 10mm Pathlength Sample and one Reference Cell maintained at Temperature range of 5°C to 90°C, according to selection of water recirculator system (optional purchase of PCB-1500 P/N 980-09081). Water pipe connectors: 9 mm. Note: The Four-Cell Sample Compartment Unit (P/N 206-23670-91) is necessary.