... RPM Tachometer Work with encoder/switch/other signals for measurement of RPM,HZ,line speed,level 4/5/6 digit display. Digital RPM ... switch, encoder, etc. Or power frequency(AC 0- 600V),range 0.01Hz--100KHz, resolution: 0.01Hz. Display digit & modes: 4 digit display ... 350g. Models: Model and TypeOutputPresetDisplaySizeNoteFA4-4NB No output 0 preset 0.1-9999 48*48mm FA8-4RNB Relay output 1 preset ...