This is an inner mold for ZH Racing rear tires, commonly used in Hang-On Racers. It's the "C (Expert)" type. Made with a 3D printer. The product in the first photo is what you will receive. (The exploded view in the third photo uses the B type (red).) Measured for ZH rear tires, it's slightly larger than the tire's inner diameter. Compared to B, it has a higher center profile, making it easier to lean into turns. *In other words, it has "less stability."* If you've tried the "B inner" and want a bit more action, try this C type. Note that due to the slightly larger outer circumference, some modification is required for the kit's original swing arm and part of the lower section of the optional oil damper (see photo 5). Weight: "18.0g for the inner mold only," and approximately "64g including the tire and wheel." The dimensions of the wheel and inner mold are properly adjusted, so "tires can be set without adhesive" (see photo 4). (Use adhesive if you have concerns when using a high-power motor.) After a year of making and testing, changing the shape and testing again, I've created something that roughly meets the required conditions. I hope you'll give it a try. Shipping will be via "regular mail." Instant purchase is OK without questions. By the way, I am the aforementioned "Chevron Models." Made with a 3D printer (0.1mm layer thickness for precision) and assembled and finished by hand, so I can't produce many. Therefore, it cannot be distributed through wholesalers or retailers like our other products. (We have set the price excluding the markup for direct sales.) Thank you for your understanding. Thank you. Type...Radio Control