Keeping an eye on the the heat is a Freeze Shield automatic heating system that prevents water from freezing or damaging the spa. There\'s a power-saving, timer-controlled heating system too.Monitoring the chlorine levels is a ChemConnect dispenser which keeps a close eye on the amount of chlorine bubbling in the hot tub. Only you will be able to monitor how relaxed you are feeling, but you can by up the ante on the massage system by adjusting the 120-jet soothing AirJet bubble massage system.Capacity: 2-4 adultsWater Capacity (80%): 669 L (177 gal.)Inflated Size: 1.80 m x 66 cm (71\" x 26\")Inner Size: 1.32 m (52\")Actual Water Flow: 1,325 L/h (350 gal./h)Heating System: Approx. 1.5-2.0˚C/h (3-4˚F/h)Max. Heat Capability: 40˚C (104˚F)Maximum water depth: 52 cm (20\")Soothing AirJet bubble massage system (120 jets)Ultra-strong DuraPlus walls are stress tested to offer durabilityFreeze Shield automatic heating prevents water from freezing & damaging the spaProgram the spa heater up to 40 days in advance for future useChemConnect dispenser provides a stable level of chlorine throughout the spa7-Color LED light uses 3 AAA batteries (not included)Power-saving, timer-controlled heating systemDigital control panel & spa pump with integrated filtration system includes cup holders and is accessible from inside the spaReinforced cover with safety lock clipsContents: 1 spa, 1 pool cover, 1 spa pump, filter cartridge (VI), 1 ChemConnect dispenser, 1 LED light, repair patch, AirJet system