HeatTech 40-80 sqft Electric Radiant In-Floor Heating Cable System, 240V Area Coverage: 40 sqft @ 2" spacing; 60 sqft @ 3" spacing (recommended), 80 sqft @ 4" spacing. Heating Cable Length: 240ft + cold lead (10ft) Voltage: 240V; Output: 720W (3W/ft.); Amperage: 3 Amps Heating cable is only ~1/8" thick and will not raise the floors significantly. UL listed for USA and comes with a 25-year Manufacturer Warranty