We are pleased to have designed another product to make roof vents easier to fit. 
We know what a struggle fitting roof vents over the ridges of the van roofs can be so we have designed a fill in bit that sits inside the ridges. These are shaped for the Fiat Ducato Peugeot Boxer Citroen Relay only due to the contours of the ridges.
Made to Last from High Density Material 
Please do not expect a perfect fit as 
We allow a slight gap to allow your bonding or sikaflex to form an effective seal all vans can vary slightly
or if a roof light has been fitted previously and ridges have been squashed down which is out of our control please view the pictures and a short youtube video to see how we use the bond and seal on the profiles. 
https://www.youtube.com/watch?v=-m8CisfV4Cc
Comes in packs of 2 if you require more just change the quantity so if you put quantity 2 you will receive 4
Unfortunately due to cost of materials and the weight we have had to increase the price but it is a new improved material and we believe its worth the extra cost
VAT Invoice supplied for business users
 
Fitting is easy all you need to do is 
Clean the roof we use a brake cleaner also clean the plastic insert.
Bond this down into the ridge making a flat surface all the way round so the roof vent will sit on it.
 Add butyl tape to the roof vent then bond down 
finally go around the outside with a bead of bond and seal 
I have shown examples of how we do it in the pictures above 
Tried and tested by converters for converters