Free thermal socks with your purchase! Never let your toes go cold again with these rechargeable insoles . Designed with your ultimate comfort in mind, these insoles are ergonomically shaped and contoured to give you that tailor-made feel. Thin enough to work with virtually any shoe, boot or even slipper, they are still thick enough to provide perfect levels of cushioning to help keep your feet warm even when not switched on. It is of course possible to trim these insoles to size to obtain the perfect fit. We've also included a handy carry bag! Features Wireless battery system - self-contained system means no fuss or external battery boxes Advanced far-infrared heating element distributes heat gently and evenly Adjustable to your shoe size - trim the soles for the perfect fit following size guide Charge anywhere - charge anywhere with any micro-USB car charger or battery powered micro-USB charger pack, existing USB wall plug, PC or laptop port Waterproof design - perfect for hiking, fishing and other outdoor hobbies Specifications Small - US: 4 -6, EU: 36-38 Medium - US: 6.5-8, EU: 39-41 Large - US: 8.5-10.5, EU: 42-44 XLarge - US: 11-12.5, EU: 45-47 Li-Po battery and USB cable Unisex design is ideal for both men and women These rechargeable insoles are also available with a handy remote: With remote Far-infrared Heating Element Like all Warmawear products, these insoles have been designed with convenience and comfort in mind. The far-infrared heating element is placed beneath the toes, as this is the part of the foot most susceptible to the cold. The infrared technology provides gentle, soothing heat for up to 2.5 hours . It can also aid in the relief of Raynaud's Disease Raynaud's Disease or Raynaud's Phenomenon Dr Rob Hicks First described by Maurice Raynaud in 1862, Raynaud's is thought to affect as many as 10 million people in the UK. Extreme cases suffering severe pain in the extremities when exposed to temperature change. and mild arthritis by helping to increase blood flow and keep extremities warm. Rechargeable Battery - 2.5 Hour Life The battery used in these insoles is rechargeable , and can be used for up to 2.5 hours at 50Â°C. This time can be further increased by only switching the insoles on for short bursts as needed. The cable plugs into a convenient micro-USB port in the side of the heel, so there is no need to remove the battery in order to charge. The insoles also come with a USB cable which can be used for both insoles at the same time, using any existing USB wall plug, PC or Laptop. You can even charge these insoles on the move with any other micro-USB car charger or battery powered micro-USB charger pack. Trim to Size These insoles can be trimmed to achieve a perfect fit and are completely waterproof . This makes them versatile, and means that they can fit into many different types of footwear. They are perfect for anyone who works outdoors. Handy Carry Bag The handy carry bag included with these insoles ensures they are kept protected when not in use. With a handy drawstring at the top, this insole can be hung up when not in use, or to store out of the way. Waterproof Design These practical insoles are also completely waterproof , so you can carry on using them no matter the weather. This makes them perfect for taking on hiking or walking trips , fishing or to the seaside Warm AND waterproof! Fully Tested in Iceland Our buyer, Alena, took a trip to Iceland to test our Warmawear products. Alena took a pair of Warmawear rechargeable heated insoles that she had pre-cut before leaving the UK to fit her hiking boots. They kept her feet warm during the glacier hike, despite walking on ice the entire way. As these insoles are also waterproof, her feet were also protected from the cold that water can bring. Click here to read more about putting our Warmawear products to the test in Iceland. With thanks to Ms P for this video of our heated clothing.