There are several different options for mounting 1A towers to a shell. The options for are:
1) Side Loader Brackets (PN 8008002) - Used when there is a narrow space to mount the bracket, like between a window and the top of the shell. Dimensions:: 5-3/4" x 15/16" x 13/16”
2) Wide Body Brackets (PN 8008001)- The WideBody extends outward more to give added clearance for square-sided shells and may make it possible to mount the bar lower to the roof. This are typically used with the 1A Towers with HighRise Spacers . Dimensions: 5.5" long x 2.25" wide.
3) Top Loader Brackets (PN 8008005) - Used on top of the shell or camper, can also be used with the Q-Tower and Q-41 clip. Dimensions: L 7.10” x W 2.50” x H 0.75”
Instructions for all three brackets are attached.