Testers have racked up 14 000 miles in the new TIDELINE testing SUPERLITE technology. This new technology has been designed to reduce weight and make these the lightest GRUBS boots in our collection. At just 1kg per pair and created to mould around your foot they offer support in all weathers throughout the day. FIELDLINE 4.0 is insulated and waterproof with excellent grip made for all day comfort. The Calve height boot is perfect for those who do not enjoy wearing a full-length wellington but do not want to compromise on the quality.4MM INSU-FOAM ULTRA -gives all round foot comfort and insulation.5mmPOLYOU footbed - provides a soft cushioning for an athletic shoe feel. Amillion microscopic nitrogen bubbles that insulate the wearer from cold surfaces. UNDERFOOT CHASSIS - give a sure-footed platform. SUPERLITEtechnology - makes this boot 30% lighter than conventional rubber boots buoyant and extremely comfortable thanks to its\' moulded shape. SUPERDRI lining - is hard wearing and wicks moister away from the wearers foot to prevent a sweaty and uncomfortable feel. It is fungus and rot proof so will not smell like cotton-lined boots. TRAIL-GRIP IIoutsole -superior grip on a variety of surfaces because the tread is designed to work with the action of the foot. COMFORT RATING - -20c to +20c. We recommend purchasing the same UK size as your regular daily footwear such as a trainer. Grubs Boots have a 15mm allowance for a wool blend / thicker sock which also means if you are a half size we recommend sizing down.