I used my Rinsekit heating element rod and mounted through a bulkhead fitting I affixed into my Engel65 hardsided cooler strapped down on the upper helm(top of my pilothouse) of my 2520 Parker charter boat for my guests to be able to have a nice warm (gravity fed) shower when finished diving for the day, The engel cooler works so well (unlike yetis) because the lid seals tight so water doesn't leak out the lid when it's latched and on the wavy ocean. The water is still warm even 18hrs after the heating element has been turned off, I drilled a 1/2" hole in the back corner of my lid and used 3M 5200 to seal a pieace of 1/2"OD vinyl tubing so the cooler can breath to have water come out at the shower head, I will buy another Rinsekit probe if it ends up failing