The Unico System® UPC-25R4-4 Supply Tubing, 2 in ID, 25 ft L, 35 cfm, Aluminum
The Unico System® Supply Tubing, 2 in Inside Dia, 25 ft Length, 35 cfm, 125 to 1000 Pa, Aluminum
The Unico System supply tubes are available in either 2 and 2.5" I.D. (inside diameter). They are often reffered to as Sound Attenuator due to the sound deadening properties of the duct. The tubes core is made with nylon, which is then wrapped with insulation and finally wrapped with an outer vapor barrier to stop moisture and also to reduce thermal losses.