California Proposition 65: This product contains a chemical known to the State of California to cause cancer. California Proposition 65: This product contains a chemical known to the State of California to cause birth defects or other reproductive harm.Locking clamps have swivel pads that help protect work surfaces from damage. Take a look at the features for Irwin Vise-Grip Locking C-Clamp. Material: Steel, Finish: Nickel Plated, Throat Depth: 1-1/2".