Eberspacher air duct 60mm, I am unable to find 1m lengths. Also is length at min or max extension? If at minimum what is the extensions ratio? e.g. 1:1.5 meaning 1m compressed is 1.5m extended. (Same for 50mm as yet to decide on set up.) Thank you.

Thank you for your question. You will find the metre lengths at the following link - https://www.butlertechnik.com/item/Eberspacher/or-Webasto-Air-Ducting-60mm-CUT-TO-LENGTH-102114310000-398497-Meter-Lengths/5JL

When you order a quantity of 1 of you will receive a 1 metre length. If you ordered a quantity of 2, you would receive a length of ducting of 2 metres. We can supply up to a 20 metre uncut length. We do not measure the ducting at extended or minumum lengths, and we do not stretch it when we are cutting to length. The same is applied to the 50mm ducting. This product is not intended to stretch beyond it's delivered length, please order the length you require without any consideration  for 'stretching'.