Thank you for viewing! This is a great value set that allows you to try out universal round mouse feet made of different materials. They are 6.6mm in diameter and 0.8mm thick. There are 60 pieces in total, with 20 pieces each of three types: slide-focused (2nd photo), quietness-focused (3rd photo), and abrasion-resistance-focused (4th photo). The soles in the photos each have a protective film, and there are actually two white and one black. Only the abrasion-resistance-focused model is made of ultra-high molecular weight polyethylene (UPE) for superior durability, while the other two are made of low-friction PTFE. Regular round soles often have a concave center due to the manufacturing process, but these soles have reinforcing material inside and a two-layer structure to prevent this. Please note that a tool for removing the soles is not included. We will ship within 24 hours of purchase (may not be possible due to personal circumstances). The product will be wrapped in cushioning material and packaged to prevent it from getting wet. Regarding the feel of use: - Used devices - The mouse is Sprime PM1, with four quietness-focused soles attached to the top and bottom. The mousepad is Artizan NINJA FX Zero X soft. If you are using a soft mousepad, you should attach 8 or more soles. If there are too few, the contact area will be small, and the mouse will sink into the mousepad, making it easier to feel friction. The slide-focused ones are the blue ones in the photo. The material is 100% PTFE and slides very well. If you are using a hard mousepad, such as glass, you can reduce the number of soles, as the mouse is less likely to sink in, so it is recommended to reduce friction with fewer soles. The quietness-focused ones are a middle ground between the other two. They slide moderately well, and the sliding sound is quieter than the other two. The material is 100% PTFE, and it is recommended for those who use cloth mousepads. The abrasion-resistant ones are the black ones in the photo. The material is 100% UPE, and the sliding is more restrained compared to the other two, so it is recommended for those who prioritize control. Also, it is resistant to abrasion, so it is recommended for those who want to reduce the frequency of sole replacement. #MouseSole