Caterpillar knows working hard shouldn’t mean uncomfortable, so they developed Ease – Engineered Comfort, a proprietary foam midsole that is 30% lighter, more shock absorbing and more flexible than standard EVA. Now your shoes can work even more for you while you stay comfortable, safe and hard at work. The P90715 Parker Chukka boot has a full grain leather upper, built in electrostatic dissipating technology to prevent on the job static buildup, nylon mesh lining, dual density EVA sock liner, and a slip and our resistant polyurethane outsole. Steel Toe. ESD Rated.