This is a pre-flexed MS chassis. (Axle retained) *This product is Sugiyama-style flex. Please attach the springs as shown in image 2. The Sugiyama style is characterized by minimal unit play, resulting in the fastest chassis currently for acceleration, banking, and corners. Using a milling machine to reduce the amount of manual work as much as possible results in a chassis with fewer product errors. Flex operation has been confirmed during production. It moves well, has high vibration damping, and is a chassis with good drive efficiency. Although a new chassis was processed, it is considered "like new" due to being a processed product. Springs are not included. Please use the black springs included in the AO1034 Slide Damper Spring Set. If you let me know in the comments before purchasing, I will send the spring set together for an additional 198 yen. Be sure to apply grease to the moving parts during assembly. Mix the blue and red grease from the No. 15471 HG Slide Damper Grease Set and adjust the damping force to your liking. If you let me know in the comments before purchasing, I will send the HG Slide Damper Grease Set together for an additional 440 yen. Processing Options You can choose the flex stroke length: long, medium, or short. (Free) If not specified, it will be made with medium. (V-cut flex is basically short only. Medium or longer requires consultation) The bottom of the front and rear units, and the parts where the counter touches during movement, are intentionally not processed (due to individual preferences). I will process them for free if you let me know. Lightweight processing (weight reduction & battery drop) +1000 yen Front and rear unit step-up processing is possible with a milling machine. (If the step-up height is not specified, it will be 1.8mm) +800 yen (If processing only one side, +500 yen) Center chassis bottom surface milling +1000 yen Rear bumper arch cut +500 yen Change to reinforced front and rear units No. 15367 N-02・T-01 reinforced unit +330 yen If purchasing multiple items at the same time, 210 yen off from the second item onwards. Please let me know in the comments before purchasing.