Xray X4 aluminium & brass chassis T-braces
From Xray for the X4 is this are two new chassis T-braces, in aluminium and brass. Designed to make the car more stable, it generates more rear traction and allows chassis flex adjustments to alter steering characteristics by adding and removing screws from the brace. Brass material puts weight (8 grams) in the centre of the chassis and helps to lower the CG.
Source: Xray [teamxray.com]