You are buying a Tecmark Pressure Switch that features 1/8th" MPT Standard Threads and 2 Spade connectors for attaching the 2 wire connections this kit also has an 1/8" Barb adapter and a 1/4" barb adapter with 3/8" and 1/4" compression adapters. This Switch fits Balboa, Gecko, ACC, Hydroquip, Len Gordon, Maddux and most other standard Hot Tub Heater Tubes. What goes wrong with these switches is either the Switch does not close when the pump comes on and puts pressure on the switch or it doesn't open when the pump goes off. If either of these things happens you will have a flo code on most systems. The are other things that will cause a flo code like an inoperative pump or a stopped up filter so be sure the switch is bad before replacing. This part used in most hot tubs that use digital control systems with low current draw across the switch 1 Amp or less if your system Is an Air Button Style and has the heater power running through the switch you would use a 20-25 Amp Switch This system is rare and usually a 115V Air Button system only. The Pressure Switch in this auction will not work in that application. We have plenty of these. Buy with caution I Do Not Accept returns! WARNING: DO NOT ADJUST THIS SWITCH IT WILL VOID THE WARRANTY!! CONTACT ME AND I WILL HELP YOU FIGURE OUT WHATS WRONG. IF YOU HAVE TO ADJUST THIS SWITCH MOST LIKELY THERE IS SOMETHING ELSE WRONG AND ADJUSTING THE SWITCH WILL NOT SOLVE IT LONG TERM!!