PETOL EL-MAC SURGRIP VALVE WHEEL WRENCHES are made from aluminum-magnesium to minimize sparking and have a fist-like head to reduce slipping even on stubborn valves. The wrenches are designed for use in the petroleum, petrochemical, pulp/paper, mining, marine and power generating industries. WARNING! - Protect yourself and others from SERIOUS INJURY! Use as a hand tool only for gripping ??? NOT FOR STRIKING!. Never use a cheater or other means to extend handle! Always pull toward base pad! If wrench slips you can be hurt or injure others.