A strap harnesses the battery and velcroes below the knee, or ankle if preferred. The heat element lies within a thin sheet of transparent flexible plastic which slips neatly into an underfoot sock-pocket.

The beauty of Warmthru Heated Socks, beside the impressive heat, is the modular construction. The sock is separate from the element which makes washing easy - simply remove the element and either hand-wash or machine-wash the plain sock. This means no danger of damage while washing. It also permits easy replacement of any piece; sock, battery, charger, heat element. You can buy a spare pair of socks at time of purchase and an extra heat-element to keep as a spare. Socks come with Li-Ion rechargeable batteries - if you want batteries with an on-off switch you can buy these in addition quite cheaply at time of purchase.