This is the Mugen MBX8 Clear Lexan Front Upper Arm Wing from Ultimate Racing. It is an aero option that attaches directly to the front upper arms. This tuning option helps to increase front end grip and traction at higher speeds, while helping to improve the front/rear balance in the jumps.
These Lexan wings are feather light and include lightweight machined mounting brackets that create a strong and lightweight mount for installation. It also includes the four screws.