ESD-4039 Electric IR Indoor/Outdoor; Dual Bulb; 39'' Long; 4000 W: 208 Volt electricSchwankheating systems offer a streamlined, yet effective heating solution for any indoor or outdoor spaces. They are available in a range of sizes, wattages, and voltages that can provide appropriate warmth to any indoor or outdoor area, from a small room to an expansive open-air commercial space. Available in single or two-stage (duel or single bulb) and models range from 500W to 6000W. Flexible Mounting Options include wall, ceiling, flush/recessed and post-mount.As opposed to free-standing patio heaters, this heater's overhead mounted design frees up space in aisles to allow more room for seating and foot traffic. Flexible Mounting Options include wall, ceiling, flush/recessed and post-mount. As opposed to free-standing patio heaters, this heater's overhead mounted design frees up space in aisles to allow more room for seating and foot traffic. Insulated cabinet, means you can mount much closer then others. Blend Seamlessly. This attractive black coating allows the heater to blend into the patio or outdoor environment. Single bulb, medium wave quartz bulbs Available in single-stage and 2-stage.