Thank you for viewing! Thanks to you, many customers have purchased our product. We are confident that our rubber is the most affordable, and it will restore a firm hold. This rubber is imported in bulk from Thailand by a Japanese rubber manufacturer and meets the required standards. Some sellers of similar products warn against cheap, inferior products, but unlike medical catheters, these are general-purpose items, so there is no difference. I keep my profit margin to a minimum. With just this rubber, there's no need for the same quality as medical-grade; the important thing is whether it can securely hold your violin. The photo shows a KUN shoulder rest with the deteriorated rubber replaced. The tubes are made of natural rubber. They are sold in sets of 4. If you would like to purchase multiple sets, please let me know in the comments before you buy. This product is for 4/4 size KUN old-type claw rubber replacement. We do not know if it will fit other fractional sizes or shoulder rests from other manufacturers. If the rubber deteriorates, your violin may slip and fall, so we recommend replacing it as soon as possible. The rubber is slightly longer or cut to the exact size, so please cut off any excess with scissors. We will ship via regular mail, but we are not responsible for any postal accidents. We usually ship on the same day or the next day, but because we use the post office, shipping may take longer if your purchase falls on a weekend or holiday when the post office is closed. It usually takes about 3-4 days on weekdays. (Excluding weekends and holidays) Due to post office circumstances.