These knee pads meet NFPA 70E standards for protection against electrical arc flashes for personal protection equipment (PPE) Category 2. Check the PPE category and minimum arc rating provided for your workplace, and then select all required clothing and personal protective equipment to meet the minimum arc rating. Arc rating measures a garment’s ability to insulate the wearer from burns; the higher the arc rating, the greater the flame resistance. These pads have a hard plastic cap that reduces resistance, making it easy to slide on hard surfaces. They have two adjustable buckles to modify the fit.