Delta Fin TF comes in two sizes; Delta Fin TF1 with 3/8in integral fins on the top and bottom, and the Delta Fin TF2 with 1.0in fins. The Delta Fin provides the necessary heat with very low water volume, resulting in high efficiency and a quick response time. Basically, the fins heat the greenhouse from below the bench, which results in maximum temperature control and accelerated plant growth. It is manufactured with high-quality hardened aluminum to be durable and rust free. With the pop on aluminum coupler, installing the Delta Fin TF is quick and easy.