Features: Size 48x96m/m Bright LED display for obvious reading Two facility(PRM/FEET/YARD/METER)WITHIN ONE METER Auto-range selection. easy to use BUILD-IN QUARTZ TIME-BASE CIRCUIT Digital circuit design with high precision and high stability Broken-line indication of signal single chip cpu I.C. for steady indication and accuracy Roller diameter and pulse/rotary are settled on front panel Hi/Lo two individual terminal for different linespeed signal in-put diaplay: 0.56'''' high red led display Accuracy: ≦50 ppm Measuring-range: 0.10~99999(Auto-range) Max. in-put frequency +12v-p. In-put terminal in-LOW SPEED: 1-30 CPS in-high speed: 31~4500 cps Range selecton: Auto-range Over-range indication: Display '''' HHHHH'''' and flashing Signal-off indication: display ''''00000''''and flashing Sensor broken-line: display "12" and flashing Time base: 4.0 MHz and so on