Ducting Heat Shrink Joining Sleeves (Pair) 70mm ID x 50mm Long An engineered solution to the problem of joining intake hose to ducts etc. The Revotec heat shrink sleeves are adhesive lined producing a strong neat light and water/vibration proof joint. They have a shrink ratio of 3:1 ie 90mm will shrink to 30mm Simple to use with heat gun. Available in three sizes 70mm 90mm and 122mm. Supplied in pairs.