If you work with foreign cars, the Proto J5321M 21mm Deep Socket is a must-have. It can remove stubborn bolts and nuts that other tools cannot. The deep socket has 12 points for superior torque and grip. Made of alloy steel, it resists corrosion and has a chrome finish for protection against rust. The drive size is 1/2 in., which fits most domestic cars as well as many foreign models. If you want to get your job done faster, the Proto J5321M Torx Metric Socket is what you need to have on hand.