This is a hot neck ring that warms your neck with a heat effect of approximately 50°C. #mmm's Room Product List - Product Name: Hot Neck Ring - Temperature: Approximately 50°C - Color: Brown - How to Use: Heat the liquid to use - Condition: Unopened No power or batteries required. Can be boiled and reused ☆ The actual product is shown in the first photo. ● Color: Brown ● What is a Hot Neck Ring? It contains a liquid that crystallizes when impact is applied to the main body, instantly becoming warm. How to use: Remove the cover of the main body and press the oval button inside with a "click" to start crystallization. It stays warm for about 1 to 2 hours, but this product can be regenerated by soaking it in hot water of 80°C or more for about 10 minutes. (It is best to put it in boiling water.) Thank you for viewing.