Designed for use on aluminum, copper, weatherproof coated wire, PVC covered conductors and messenger and guy strand. The Chicago style grip was designed for cable sizes from 0.218-Inch to 0.55-Inch (5.54 to 13.97 mm). When pulling EHS (extra-high-strength) galvanized-steel cable, the galvanizing has a tendency to coat the jaws of any grip, causing the cable to slip. Double V contour reduces the possibility of slippage and damage to the cable.