Type 12 T-rail suspension is a cost-efficient method of suspending D-shaped ducts, ideal for low ceilings and frequent laundry, as it is quick and easy to remove and replace the ducts. The T-rail, so named because it looks like a T in the cross section, is made of anodized aluminum, making it an excellent choice for corrosive environments. Two T-rails are fixed to a hard ceiling and the duct is then suspended from the rails. The duct will have sliders that slide down a channel in the T-rail at the 3 and 9 o’clock positions. The length of the duct straps that hold the sliders can be manufactured to specification.