Grubs Ladies Tideline 4.0 Boots Olive Green. Keep your feet warm and dry in extreme conditions with the Tideline 4.0 Boots from Grubs. Designed to be waterproof and insulated, the Tideline offers excellent grip to allow to you to go anywhere is absolute comfort. With a calf height design, the Tideline Boots features 4mm insu-foamultraâ ¢ to allow for all round foot comfort whilst the Superdriâ ¢ lining provides a hard wearing, moisture wicking liner to provide all day comfort whilst preventing rot and fungus growth and reduces any unpleasant odours. With a 5mm Polyouâ ¢ footbed and a Trail-gripâ ¢ outsole provides a soft cushioning feel due to the million microscopic nitrogen bubbles to help insulate the wearer against the bitter cold whilst providing superior grip to a variety of surfaces. With an underfoot chassisâ ¢ for a solid footbed, the Tideline features Superlite technology allows the boot to be 30% lighter then conventional rubber boots. This allows the Tideline to be extremely comfortable and buoyant with testers racking up to 14,000 miles. Superlite technology allows the boot to mould around your foot and only weights 1kg! Offering a comfort rating between -20 ºC and +20 ºC the Tideline 4.0 Boots provide a range of useful features from a larger toe space for comfort, contouring to the arch and shape of the foot for maximum support, technology to relieve pressure on the instep and ankle support to ultimate comfort and support.