Inner mold for ZH Racing rear tires, commonly used in Hang-On Racers, is the "A (Mild)" type. Made with a 3D printer. The product in the first photo is what will be sent. (The exploded view in the third photo uses the B type (red).) Measured ZH rear tires and made them with a size that leaves a gap of a few tenths of a millimeter with the tire. Compared to B, it has a slightly flatter profile, resulting in a more stable specification. If you "tried the B inner" and want a little more stability, please try this A. Weight is "16.2g for the inner only" and about "62g with tire and wheel". The dimensions of the wheel and inner are appropriate, so "you can set the tire without adhesive" (photo 4). (If you are using a high-power motor and feel uneasy, please use adhesive.) After a year of making and testing, changing the shape and testing again, we have created a product that roughly meets the required conditions. We hope you will try it. Shipping is via "regular mail". Immediate purchase is OK without questions. By the way, we are the aforementioned "Chevron Models". We create with a 3D printer (0.1mm layer thickness for accuracy) and assemble and finish by hand, so we cannot produce large quantities. Therefore, it cannot be distributed through wholesalers or retailers like our other products. (We have set the price excluding the margin for direct sales.) Please understand. Thank you. Type...Radio Control