Acoustic meters; Appliances for measuring the thickness of leather; Borescopes; Bubble levels; Digital pH meters; Electronic apparatus for testing compression, strength, hardness and tensile characteristics of industrial materials; Frequency meters; Lasers for measuring; Protective work mittens; Spirit levels; Stroboscopes; Surveying apparatus and instruments; Tachometers; Tension testers; Tool measuring instruments; Ultrasonic thickness gauges; Vibration meters