ALUKAP-XR rafter gaskets help with any expansion and contraction thanks to their special lubricant which is safe for use with coated glass units. They ease any friction build-up between the glazing system and rafters and come pre-lubricated so all you need to do is install them. Available in 45mm and 55mm widths for use with ALUKAP-XR standard bar sizes.ALUKAP-XR is a weather-resistant glazing bar system from Clear Amber that sits atop rafters for a clean, attractive finish. The sturdy and durable system comes in a range of profiles and finishes, in both white and brown so you can match the rest of your building or surroundings with ease. Compatible with timber rafters, the fixings for ALUKAP-XR are concealed and made from aluminium like the rest of the system so youre assured quality and neat installation. Decorative finishing castings are also available so you can bring even more style to your system.Rafter gaskets are optional to make installation of ALUKAP-XR glazing bars easier. For every 1m of ALUKAP-XR glazing bars ordered, you will require 1m of rafter gasket if you do choose to use them.