This unit, the smallest 9,000 BTU on the market. It is almost the same size as the Mermaid M6 unit. In order to keep the smallest footprint on the market, we utilize the same stainless steel base as the Model M6 - 6500 BTU unit. This unit is available in right, left, or top air discharge configurations, and is available as a "Cool Only," "Cool/Electric Heat," or "Cool/Reverse Cycle Heat." We use a 6" and 4" ducting and recommend a minimum of three 4" round supply grills with this installation. The electric heat option generates 5,640 BTU of heat while the Reverse Cycle generates over 10,000 BTU's. Electric heat is not available in 220/240 Volt configurations.