This is an adapter for Tamiya formula chassis to use 12mm hub wheels on the rear. Originally, it seems that the F103GT parts could accommodate 12mm hub wheels, but they are almost impossible to obtain due to the manufacturer's shortage. So, it's faster to make it than to search for it! That's why I made it♪ I made it to fit the F103RX, a very minor chassis, so I don't know if it can be used with other formula chassis. (Someone, please be a guinea pig, lol) How to install: • Move the shaft as far as possible to the R side and fix it with a set screw. • Assemble the differential as usual, insert the thrust bearing set and the disc spring into the shaft, insert the right side adapter, and attach the wheel (right side completed). • Insert the pin into the Tamiya axle shaft and insert it into the left side adapter. • Insert the spacer on the left side as usual, insert the left side adapter, and screw it in (left side completed). Therefore, you will need a Tamiya axle shaft for installation, so please prepare it. I designed it to have roughly the same tread on the left and right sides, but If there is any deviation, please provide feedback. I used the disc spring as is, but You can hardly adjust the ball differential, lol. Please be aware of this beforehand m(_ _)m The material is black carbon-mixed resin. Notes: • Since it is 3D printed, the strength and accuracy are moderate. • Due to the structure, the L side may inevitably have shaft wobble, so please use it in a state with less wobble by retightening, etc. • Basically, it is for drifting only. It might be usable for grip, but I think the strength is insufficient, so please do so at your own risk. • Please purchase only if you can laugh and forgive if it breaks immediately m(_ _)m