This part is a 5.5KW Titanium Heater Complete Assembly includes Tube, Element, Metal Case and connecting wires. This unit features a high limit holding tab and a port for the pressure switchThis Heater Fits Cal Spa Hot Tubs and Is a Perfect replacement for the XL Heat Exchanger. The biggest difference is this Heater has a replacable element the XL Heat Exchanger doesn't you have to replace the entire heater when it fails. In the picture portion of this Item you will see an original heater mounted in the tub and burned on the left side this heater was engaged while there was no water in the tub and it caught on fire. A regular heater like the one you are purchasing will not catch on fire like that. The other two pictures are of the outside of an XL Heat Exchanger and the inside of one that burned and was tripping the breaker.  

Aftermarket Replacement for Cal Spa XL Exchanger
This heater assembly is not an exchanger but an in-line flow thru replacement. This heater assembly is designed as a drop-in replacement. 2" x 15"s/s housing with 2" slip tailpieces, dual thermowell grooves w/cover, 1/8"npt pressure switch tap, and metal box. Pressure switch not included

Note: The Company that was building these heaters originally has gone out of business therefore the heater available now no longer have and insulation wrap or a mechanical hi limit.. The reason is the element now is inside the water so you don't need either of those things like you did when the element was on the outside of the tube like the original heater you are replacing.. The great thing is in the future if you need to replace the element you can without replacing he entire housing..

Heater Application    Cal Spas
Heater Length    15"
Heater Type    Flo Thru
Housing Configuration    Straight
Housing Diameter    2"
Kilowatts    1.375kW/5.5kW
Pressure Tap Orientation    0 Deg from Terminals
Voltage    115v/230v
Heater Inlet Size    2"
Heater Inlet Type    Slip (s)
Heater Outlet Size    2"
Heater Outlet Type    Slip (s)