Additional extension curb with flange for installing RoofLITE+ FRE and FRF flat roof windows.

If your project to install a RoofLITE+ FRE or FRF window in a flat roof requires the use of an extension, you should use the optional FRC.F extension curb. This extension curb with flange raises the window by 16 cm. 

Up to three additional FRC elements can be used if a higher rise is required. Each of these raises the window an additional 15 cm. This means that the overall height can be increased by 61 cm.