Frequency Meter 56-65 Hz 120 Volt with 10 LED Bar DisplayDirect Read LED Frequency Meters Utilizes a 10 Segment LED DisplayMeter Requires 12 Volt DC Supply to Power LEDsMeter Scale is Labeled 56, 60 and 65 Hz ACSquare Panel Meter Mounts in 1.75″ Diameter Round Hole.Dimensions: 2″ (W) x 2″ (H) x Overall Depth: 1.75″Mounting Studs are 1.5″ Center to Center Horizontal & VerticalMeter Input: Screw Terminals with Solder terminalsIncludes: Mounting HardwareBocatechBTBM-56-65HZ