This flexible chassis has been significantly modified from the jig-built flexible chassis. The specifications are as follows: Reinforced Unit Used "Changed to N-02T-01 reinforced unit" Underside Raised Liner Included "To prevent the chassis bottom from hitting the ground when using 23mm tires, the chassis bottom needs to be raised. A liner is inserted to raise the bottom by about 1mm and polished." Battery Cover Removed "Battery is held in place with a rubber liner for weight reduction." Damping Rubber "Provides strong damping to keep jumps low and landings smooth. Black spring has been cut by one coil, essential for 3D courses." Third-Party Carbon Stays "Chassis shaft cut, using aluminum shaft black countersunk screws. Carbon prevents sagging and securely fixes the shaft, making it durable and eliminating irregularities." Axle Hole Reamer Applied "Axle holes vary in size, and some may not fit 620 bearings, so they have been expanded with a 6mm reamer." Spur Gear Clearance Modification "The gear covers have been shaved to prevent the spur gear from contacting them." Front and Rear Bumper 1.5mm Bottom-Raised Reinforcement "Bottom raising is essential for bank through when attaching brake stays. Also, because the base becomes weaker by raising it, carbon reinforcement is applied from the inside and reinforced with black instant glue on both front and rear." Bumper Cut "The post-processing after bumper cutting has not been touched. It is recommended that you adjust it when installing AT or anchor systems." Normal Terminal Voltage Adjusted "Normal terminals, if well-polished, have better electrical conductivity and can be used longer than gold terminals, which get scratched. Each voltage has also been increased with brakes." Normal Gear Cover Screwed "Normal gear covers often come loose, so they are screwed in place. Also, it supports the motor and prevents voltage leakage. This is also essential." Counter Gear POM Support "The counter gear is supported by POM from a low-friction plastic bearing set, which is expected to increase torque due to low friction. 520 bearings are recommended for the gears." The bottom has been raised to the limit, and the switch cover is peeling off. Also, there are needle-like marks on the red liner. Please check the back side. Thank you very much.