The extensions come in different size ranges.
Please measure the total length in mm when all three pieces are put together on the window then select the correct size range that your measurement fits into.
We will then send you the correct size range extensions to be cut down to the exact size by yourself.
Sash Rebate: The total length of the opening window where the extensions are fitted.
These extensions are sold in pairs. The price shown is for a pair.
* The extensions for 320-800mm sash rebate don't have mushroom cams. The other sizes do.