The Klein Tools 1678 Chicago Grip Series is designed for use with aluminum conductors. It features round jaws that provide maximum contact with the circumference of the cable, making it less likely to cause cable deformation. All Klein grips are manufactured from custom drop-forged steel that is machined and heat treated for excellent durability. Each grip is individually hand inspected and actuated for proper function. Grips are also rigorously tested and pulled to rated load to ensure the highest quality and reliability.