Physical labor is often necessary for 8 hours or more per day with breaks approximately every two hours including stooping, crouching, reaching, standing, walking, pushing, pulling, lifting, bending, twisting, kneeling, talking, hearing, vibration, noise and engaging in repetitive motions and excellent vision. Repair machines, equipment, or structures, using tools such as hammers, hoists, saws, drills, wrenches, or equipment such as precision measuring instruments or electrical or electronic testing devices.