The FT202 sensor is a top overfill sensor and part of the FloTech brand retain/overfill monitoring system. The probe holder is cast aluminum with a 2" NPT mounting thread, heavy duty stainless steel hardware, and Viton® seals. The FT202 is mechanically and electrically compatible with the Civacon model 1050 two wire top sensor. The sensor is installed by threading it into a 2" NPT tapped hole or mounting it in a 2-3/8" hole secured by a gasket and metal locking nut.