For sale: Bath Spa bath water heater. Manufacturer: Goto Co., Ltd. Product Name: Bath Spa bath water heater Function: After filling the bathtub with hot water, simply submerge this product in the tub, and the water temperature will not drop for 4-6 hours. Thank you for viewing. This product keeps bath water warm for a certain period of time. After filling the bathtub with hot water, heat this product in the microwave for a specified time to achieve the heat retention effect. I used a similar product before, but after throwing it away, I bought this one to use again. I opened it, but I didn't use it and it ended up being stored away, so I decided to put it up for sale. The same product I used in the past kept the water warm better than I expected, so it's great for bath lovers with varying bath times, or for those who want to take a bath immediately after going out after preparing the bath in advance. The usage depends on your ingenuity. The product's stated heat retention time is up to 6 hours, but in reality, the heat retention decreases somewhat. However, the temperature didn't drop drastically even after 9 hours, so I think it's a very good product. Also, by using this product, the gas usage time is drastically reduced, minimizing the pressure on households due to the recent rise in energy costs. There are also products that heat with electricity, but this product only needs to be heated in the microwave, so the only electricity cost is the electricity used by the microwave. Therefore, you can save on electricity and gas bills compared to other similar products. Please note that since this is an unused item, price negotiations are not possible.