This flexible chassis has been significantly modified from the jig flex. The specifications are as follows: Uses a normal red chassis "The chassis has been changed to a red chassis made of ABS resin. It also includes the light dash motor and EX gear from the Advance Pack." Includes an under-bottom lift liner "To prevent the bottom from hitting the ground when using 23mm tires, it's essential to lift the chassis bottom. A liner is installed to lift the bottom by about 1mm, and it has been polished." Battery coverless "Uses a rubber liner to hold the battery in place for weight reduction." Damping rubber "Provides effective damping to keep jumps low and landings smooth. The black spring has been cut by one coil, which is essential for 3D courses." Tamiya HG Carbon Multi-Wide Rear Stay "The chassis axis has been cut, and black aluminum screws are used. Carbon is used for anti-sagging because it securely fixes the axis, allowing for longer use and eliminating irregularities." Axle hole reaming performed "Axle holes vary in size, and some may not fit 620 bearings. These have been expanded using a 6mm reamer." Spur gear relief processing "The gear covers have been shaved to prevent the spur gear from contacting them." Front and rear bumper 1.5mm bottom lift reinforcement measures taken "Bottom lifting is essential for brake stay installation and bank through. Also, because the base becomes weaker by lifting, carbon reinforcement is applied from the inside, and both front and rear are reinforced with black instant glue." Bumper cut "The post-processing after bumper cutting has not been touched. It's recommended to adjust it when installing AT or anchor systems." Normal terminal voltage adjusted "Normal terminals, if well-polished, have better conductivity and can be used longer than gold terminals, which get scratched. Each voltage has also been increased with brakes." Normal gear cover screw fastening "Normal gear covers often come loose, so they are secured with screws. This also 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 bearing installation is recommended." This chassis is designed to be durable and stable. It's a chassis that bottoms out quite a bit, so gear relief is necessary to prevent it from going through. Whether or not you increase the voltage can change the speed by 1000 RPM, so the voltage increase is considered, the motor is securely fixed, and the chassis has a solid suspension and effective damping. Thank you for your consideration.