12V Feature: 100% brand new and high quality.1. The heating material is far infrared carbon fiber, suitable for hiking, etc.2. Based on the USB-powered heating system, heat circulates evenly.3. Provide warmth and comfort, as well as safety and enjoyment, especially outdoors.4. Increasing blood circulation, helps people to be warm and even relieve the pain of mild arthritis. Specification:Power:7WOlor: as shown in the picture Max Voltage: 12VGnartial Application: Heating EarbudMaterial: Far Infrared Carbon Fiber Design Temperature: About 40 Degree Celsius Size: M(35-39)L(40-45)Package Included:1 Pair * Electric USB Heated EarbudNote:1. Due to the light and screen difference, the item's color may be slightly different from the pictures.2. Please allow 0.5-2cm differences due to manual measurement.5V Feature:Utility model of USB insert electric heating. It circulates heat evenly. Provide warmth and comfort, as well as safety and enjoyment, especially for outdoor.5v low voltage power supply, high safety, energy saving. Description:Color: as shown in the picture Max Tension: 5V Main Application: Insole Heating Material: Bendable Metallic MaterialDesign Temperature: About 40 Degrees CelsiusSize (Approx.): Large Size: 7CM*25.5CM(2.75in*10.03in) for shoe size 40 45 Medium size: 6.7CM*23.5CM(2.63in*9.25in) for size b