The 3 Seal Off sizes are designed to cover all duct sizes from 1/2" to 6". Each of the units will attach directly onto the Seal Off Body which, in turn, attaches onto the Hose Assembly. The Hose Assembly is made from crush-proof 2" hose and is 25 ft in length. At the end where the Seal Off Body attaches, there is a swivel connector allowing the body to be turned in any direction.