These Stabilser mounts give more precision when setting up your roll bars. This part needs to be coupled up with the A part (CLICK HERE) to have a pair.
The side brace stops the mounts moving, giving you a straight edge when fitting your sway bar collars or TRF one piece Stabiliser rod.
Here is an article with more info http://www.thercracer.com/2016/03/tamiya-trf-high-precision-stabiliser.html
You will need a grub screw and a 8x3mm button head screw to fit onto the TRF Tamiya.
This is a Beta Product sold to other racers to help them improve their race cars.