Suits pre M7 Balboa packs using pressure switch instead of probes, found on pre 2000 Spaform units and some after.
These units are PRE M7 (sensor style) and comes complete with a 2-PSI pressure switch. This Titanium heater is completely compatible with your old style heater, it is only the internal element that has been updated and improved.
Length: 15 inches
Diameter: 2 inches
Distance Between terminals: 1.25 inches
Complete length (inc. uniona): 19.5 inches