Grubs OUTLINE 5.0™ is designed specifically for the equestrian user who want a boot that will take them from yard to stirrup. 5MM INSUFOAM-ULTRA™ neoprene and rubber shell ankle boot provides comfort and warmth.        OUTLINE™ OUTSOLE - GRIP-GRID pad grips the stirrup for better heel position and greater control.       HARD TOE TECHNOLOGY and - Unique HARD TOE™ TECHNOLOGY AND REINFORCED HEEL - reinforced toecap and ankle protects the wearer’s during daily activities.       KICK SPUR - Designed to keep spurs in place and help wearer remove the boot with ease       Comfort Rating -20º C to +20º C   HARD TOE™ TECHNOLOGY Self-hardening layers of epoxy impregnated material to stiffen the toe of our boots to give a protective toe that can take the same sort of knocks as high-end mountaineering footwear.   SUPERDRI™ LINING Moisture wicking linings use thousands of fibre loops that cosset the foot and wick away moisture keeping the wearer dry and comfortable. Combined with 5.0 INSU-FOAM ULTRA™ to provide an unequalled comfort range without sweat and heat build up.   UK SIZE       BOOT HEIGHT   (mm on leg)   CALVE WIDTH   (circumference in mm)   UK4 140mm 400mm UK5 144mm 410mm UK6 148mm 410mm UK7 152mm 420mm UK8 156mm 420mm Grubs OUTLINE 5.0™ Rubber Riding Muck Boot Thermal Lined Neoprene Rubber