10 mm Three-layer Thinsulate boot replacement liners with integrated heated insoles

• Inner Thinsulate layer provides thermal insulation and moisture wicking capabilities
• Heat reflective foil deflects cold and keeps body heat
• External polyester layer provides premium insulation and moisture management
• Designed to fit Norfin Klondike & Hunting Forest boots
• Battery powered heated insoles
• Power bank requirements: 2 pcs 5V of 2.1aH or more
• Supplied without batteries

You also need the battery for the liner at https://dakotaangler.com/products/chargeworx-5000mah-dual-usb-slim-power-bank-combatable-w-norfin-heated-boot-liners?_pos=1&_psq=chargewo&_ss=e&_v=1.0