22mm LED round mini digital display electronic hertz frequency meter indicator lamp measuring rang AC 0-99Hz type: AD101-22Hz place of origin : Zhejiang Province,China(Mainland) brand name : NIN mounting diameter: 22mm color: white green red yellow blue display type : digital display supply voltage : AC 50-380V frequency measuring range : 0-99HZ display resolution :1HZ sample rate : about 1 time/s no input signal hint message : display 000
