The latest evolution in powerful and portable heat is here! BIG Buddy from Enerco/Mr. Heater now takes portable heat to another level --- 18000 BTU/HR with the capacity to heat up to 400 square feet of space for up to 220 hours (on low position). BIG Buddys Dual-Heating System (DHS) combines radiant heat comfort with convection heat airflow for maximum heating efficiency. Multi-position heat settings of 4000 9000 and 18000 BTU/HR control comfort level. Built-in oxygen shutoff sensor and tip-over switch ensures indoor safe operation (adequate ventilation must be provided; see operating instructions). Certified by CSA International (American Gas Association) Mr. Heaters Big Buddy Indoor Safe Portable Heater features a low oxygen safety shutoff pilot to provide safe reliable propane heat indoors. (Note: Big Buddy is presently not available in Canada). Special Features: Ergonomic Easy-Carry Handle. Low Oxygen Shutoff Pilot Safety System For Indoor & Outdoor Use. Blower Fan Power On/Off Switch. Uses optional A/C. Adapter Or 4 D-Cell Batteries To Power Blower Fan. Large 4-Position Heat Level Control Knob With Built-In Piezo Starter. Integrated Hot Air Blower Venting System. Attached Swing-Open Doors with Swivel-Out Mount For Easy Cylinder Installation. Porcelain Coated Reflector For Extended Life. Dual Ceramic Burner Tiles With ShockAbsorbing Floating Insulation. High-Temperature Coated Safety Wire Guard. Non-Skid Surface Pads For Extra Stability. Key Shaped Rear Mounting Holes For Wall Mounting. Built-In Tip Over Shutoff Switch. CSA Certified For Indoor & Outdoor Use.