General description 100% brand new, high-quality USB thermostatic insulation board designed for lunch boxes, milk bottles, and more. Ideal for outdoor activities such as picnics and school trips, this thermal warmer ensures your food stays at the perfect temperature. Technical specifications Temperature: Rises to 50°C and maintains it Material: PE Size: 25 x 14 cm Package Contents: 2 x Insulated Lunch Bags Measurement error: +/- 1-3 cm Usage Suitable for use with an insulation bag to keep your bento warm for an extended period.