... , 47~53Hz,57~63Hz,44~56Hz, 54~66Hz Frequency meters with one row of horizontal reeds are used to measure frequencies ... good market to you, which you can trust. Name: Frequency meter with reeds types Size(mm) Accuracy Type Voltage Frequency 96X96, 72X72 ... ~53Hz,57~63Hz,44~56Hz, 54~66Hz Mounting: flush mounting with bracket Frequency Meter with Reeds Types