This is a brand new, unused item. Free shipping is available within Japan without exception. No comments needed, immediate purchase is OK. We sell at the limit price from the beginning, so 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 refer to the following [How to Use]. [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 of your teeth 4. Cut off the excess parts with scissors and shape it *We cannot guarantee any injuries, such as burns, caused by improper use, so please use it 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 item 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) *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 such instances, we will report them to the Mercari office and consider legal action. Teeth grinding, false teeth, 12 pieces 736 mouthpiece apu 139 spa original 104