Noble Zip has been designed with a gusset for comfort and fit. It features a 5mm neoprene lining, and is made from tough 1.8mm natural rubber, reinforced around the foot and specifically at the heel and forend. This makes the boot both flexible and hardwearing. The outsole is manufactured from two different-density rubbers for extra comfort and to ensure a very strong bond between the sole and the boot. The boot has a central tread pattern devised to prevent the boot sticking in the mud.