GAME SolarPRO XD1 AquaQuik Swimming Pool Solar Heater Heating Coil w/ Thermostat No electricity or gas connections! Adapters for INTEX pools are included Protective cover traps solar heat in and warms water as it passes through For larger pools, multiple heaters can be connected with use of a Bypass Kit from GAME (Not included) In-ground pools require Bypass Kit from GAME for multiple units (sold separately)