From same brand
This 3-pack of Vital Heat Belts from Thermopad activates heat when exposed to air. The belts bring a natural heat thanks to the unique composition of the contents. They heat up to 48 °C (118.4 °F) and keep an average temperature of 42 °C (107.6 °F) for up to 12 hours.
The Heat belt wraps around the lower back area where it provides heat in four zones within the belt. The belt stretches in size so it will fit from S to XL.
This is a 3-pack perfect for a weekend of training in the cold periods.
Notice: Thermopad products are single-use, meaning that once activated by air, they cannot be re-heated for any purpose.