At least here in the U.S., this type of ducting is 4 inches in diameter, which is, of course, the same size as the thin aluminum (oh, Ok ... aluminium) duct work that would exhaust the dryer to the outside of the house if you had one. One can easily buy a short piece (maybe 6 inches long or so) of 4 inch ducting to join the two pieces of the plastic ducting. You'll need 2 clamps to secure it of course... If it's a tad too long after you buy it it can easily be trimmed with a pair of heavy duty scissors... if it's too short... buy another one...