Most GRUBS® rubber boots use an auto-insulating structure INSU-FOAM ULTRA™ Bootie-Konon, which acts as a neutral medium between the wearer and the outside. The bootie is both waterproof and insulating, exceeding the long-term efficiency of waterproof membranes and loft-type insulation. The boots are waterproof according to standard EN ISO 20344:2004 5.7. FROSTLINE 5.0™ is insulated and waterproof, with return grip, made for all-day comfort.5 MM INSU-FOAM ULTRA™ - provides comfort and insulation around the foot.6 mm NITROCELL™ insole - offers soft cushioning for a sporty shoe feel. A million microscopic nitrogen bubbles protect the wearer from cold surfaces.UNDERFOOT CHASSIS™ - provides safety.HEXZORB™ technology - absorbs heel shocks for comfort throughout the day.SUPERDRI™ lining - is durable, wicks moisture away from the wearer's foot to avoid a sweaty and uncomfortable feeling. It is resistant to fungi and rot and does not smell like cotton-lined boots.TRAX™ outsole - remarkable gri...
