RBL Adapter for Fence Post Kit
These two adapters are sold separately, but perfectly mate with the 4x4 and 5x5 fence cap kits.
Simply twist-lock out the clear dome and snap in an RBL adapter that will thread one of your RBLs for use during the holiday season.
There are two versions of RBLs out in the world. The original style from ReallyBigLights (not sold anymore) and the newer, more popular Home Depot versions made by their Holiday Accents brand. Check your thread size to determine which you need if you're not sure what you have.
HOME DEPOT RBL adapters
Screw-in threads are 80.5mm to 83.5mm
OG RBLs from ReallyBigLights (these lights are no longer sold)
Screw-in threads are 70.0mm to 74.0mm