Brain Sleep Mattress Protector Perfect Warm EX Single Regular price: 14,300 yen (tax included) Other bedding items are also on sale! → #spsleep [Shipping during the New Year's holiday] We plan to ship within 24 hours as usual, but depending on when you purchase, it may take 2-3 days. Thank you for your understanding. Brand new, unopened. Immediate purchase is OK. This is a Brain Sleep box sheet that warms your mattress. Single size. Quoted from below: The ultimate warm protector (box sheet) Moisture-absorbing & heat-generating, uniquely developed insulation "Kapok Heat EX" Sustainable heat generation technology that surpasses down feathers [Kapok Heat EX] A uniquely developed insulation using plant fiber [Kapok], which absorbs moisture and generates heat, and [Acrylic], which has high heat retention, and [Acrylate], which has high moisture absorption and heat generation properties. This is a sustainable material with ultimate heat generation technology that converts absorbed moisture into warm heat. Maximum +5.1℃ with the ultimate heat-generating material "Kapok Heat EX". Ultimate heating power. The Kapok Heat EX material absorbs moisture in the bed and converts it into heat. It shows a temperature increase of 5.1℃ after 7 minutes of measurement. Heat retention is about 112% UP. By using the mattress protector, it prevents coldness from below and prevents coldness on the back. The cold air in winter tends to accumulate on the floor and ground, and that cold air is felt as coldness through the bed mattress. It is effective in protecting the body from that coldness.