These are a set of 8 deg caster c hubs to improve the steering on any of the 2wd chassis that use a variant of the TL01 or WR/WT suspension. I made these for my WR02CB Comical Hornet, so they work on all of the Comical edition buggies. They also work on 2wd WT01 variants such the Bush Devil 2, VW Amorok, Blackfoot Xtreme and Blackfoot 3. They will also suit the M04 chassis.
These are 2wd only as they do not have a hole for a front driveshaft to pass through, so they are strong and stiff in the Versatile Plastic material. If you have a front or 4WD chassis on these platforms (GF01, TL01, M03, WT02) you need the offical tamiya part 54661. These are simply a cheaper option than the Tamiya part if you have 2wd.
To fit them, simply cut the joining sprues off with side cutters or a knife, then run a 5mm drill through the kingpin holes to clean them up and run a 3. 1mm drill through the lower wishbone pivot hole to clear the screwpin. Do not drill the hole for the top arm. This is sized to allow the self tappibg step screw for the upper arm to fit right in.