The CdS cell is hermetically sealed in a metal to glass case and further protected by epoxy resin in a molded plastic housing. Three standard types are available for applications requiring “turn off” and “turn on” resistance values between 10k and 40k Ohms. The sensor must be mounted with light-sensitive area facing ambient illumination. These sensors meet the requirements of U.S. Coast Guard Specification number 234.

The Buoy Vent Valve Type SV-10-P is designed to allow positive ventilation of the buoy battery pocket while prohibiting salt or fresh water from entering the vent line when the buoy is submerged and/or tilted more than 45 degrees.