The EZtankless Model EZ 101 is aesthetically pleasing and has simple design features that make this outdoor unit easy to use and install as well as unobtrusive if located within view of working or living spaces. We are the seller who tells you the straight-up honest truth. Don't be deceived by others who market similar heaters, this type of draft unit is not for indoor mounting in a residence! This unit will operate on a standard LP (propane) tank as used with barbecue grills. No electrical plug-in is required, making this LP model ideal for use by outdoorspersons during hunting or camping expeditions, or you may choose to use this heater for semi-permanent installations at long term camp sites, small lake homes or cabins, open shelters, barns, workshops and sheds, or any open area with excellent ventilation. Or for those who live in remote rustic cabins and homes with one bath. The intake air is pulled from all around the casing keeping the unit very cool to the touch. For example; As tested in our USA laboratory, this unit can easily operate via a garden hose inlet water supply. This "No pilot light" design is safe and convenient, using automatic ignition to further your energy savings. Convenient for areas where electricity may not be available. The ignition electrical source is supplied by two long lasting "D" cells (not included).