Brand new, never used. Free shipping within Japan, without exception. No need to comment, instant purchase OK. Since we are selling at the limit price from the beginning, we do not offer discounts except for irregular sales, but we will consider a discount if you purchase multiple items, so feel free to comment. This is a set of 6 pairs (12 pieces total) of upper and lower mouthpieces. There are no instructions, so please use the following 【How to Use】 as a reference. 【How to Use】 1. Warm the mouthpiece in 90-100 degree Celsius water for 5 seconds (The temperature at which it softens varies depending on the season) 2. Take it out of the hot water and cool it for 10 seconds 3. Press it firmly against your teeth to create a mold 4. Trim off the excess with scissors to shape it ※ We cannot provide any warranty if you are injured, such as burns, due to improper use. Please use at your own risk. ◆Must Read◆ To reduce the burden on postal workers, shipping on Saturdays, Sundays, and holidays, as well as next-day delivery, has been discontinued. If your order does not arrive after a week from the shipping date, please contact us as there may be a delivery accident. Also, if you wish to have a tracking number and anonymous shipping, you can change to "Rakuraku Mercari Delivery" for an additional 150 yen, so please write "I want Rakuraku Mercari Delivery" in the comments. We will change to Rakuraku Mercari Delivery as soon as we confirm your request. (We do not ship with Yu-Yu Mercari Delivery) ※ The theft of images and text infringes intellectual property rights and violates Mercari's terms and conditions and the law, so please do not do so under any circumstances. If we find any instances, we will report them to the Mercari office and consider legal action. Teeth grinding, false teeth, 12 pieces 736 mouthpieces apu 139 spa original 104