Aquatemp 4kw Tefel Coated Spa Heater Element 120/240v. This is a double bend flow thru heater element. It measures 1.25 inches from terminal end to terminal end. Overall length is 10.50 inches. This element will fit most flow thru heaters. It is 4kw when using 240v and 1.25kw when using 120v. All hardware & o-rings required for installation are included. What Tefel Coating Means? Tefel is a specially formulated high temperature non-porous coating that is applied and backed onto the element sheath and bulkheads at over 1800 degrees F. With powdered titanium as part of the coating this formulation protects the sheath from both corrosion and calcification. Along with Aqua Temps EP Bulkheads this is one of the best spa elements you can buy. Will replace part numbers 6-FLO-ET, 6-FLO-TE, 7020638TE, 9135-38, 6-FLO, 624409C.