There easy to fit instead of the 1/2 hose that comes off your pump and into your hose reel basically it will come off your pump go into the shower put an other piece of hose which will be coming out the shower hot after 10 minutes and that will go into your hose reel job done. The small gas bottle hose will go on the small outlet next to the x2 outlets for the hose pipe. Be aware when you first get it going don't forget it takes abit of time to warm up it doesn't come out hot straight away just incase you think it's not working. Also adjust the water speed with the dials and the cold and hot button as if the water comes thru to fast you will need to slow it down a tad as it will keep putting out the pilot light !!!! Hope that helps