Description Manuals Videos Articles Clemco #29768 Clemco CMS-4 CO Monitor replacement sensor. Make sure a new hydrophobic filter, #29868, and charcoal filter, #25564, are available when changing this sensor since they will be required. Related Parts (1) Parts Included (1) CMS-4 CO Monitor, monitor only #29766 $673.87 1137 Customers Also Viewed CMS-4 CO Monitor, monitor only #29766 $673.87 CMS-4 Service Kit #29870 $117.80 CMS-4 CO Monitor Package #29765 $933.43