The Tinman HVAC Drain Pan is a rectangular plenum made of galvanized steel, measuring 19 x 25 x 2 inches. It is designed for both updraft and downdraft installations and is compatible with various HVAC systems such as ducted evaporative coolers, packaged rooftops, and central heating and cooling units. With a unit quantity of 20, this drain pan is a reliable and durable accessory for HVAC systems, providing a stable and secure foundation for efficient operation.