LED Frequency Meter Model:SF-LED96-3,SF-LDE72-3 Accuracy:Class 1.5 Volt.:110V,220V,380V Frequency:45~55Hz,45~65Hz... ... 54~66Hz LED Frequency Meter1. Model: SF-LED96-3 SF-LDE72 ... -3Fastening:by means of nuts ,absolutely safe,fast,robust,side by side. 2 ...