for DC 5V 12V 36V Trigger Counter Module Accumulator Memory 4-Bit 0-9999 Red 0.56in Digital Tube Display with for Shell for Case OOTDTY QF-C04 is a trigger counter. Each for time input a trigger the calculator adds one. Returns 0 when press Clear button. Feature: 1>.Wide input 2>.4Bit Red digital tube display 3>.Low level trigger Parameters: 1>.Item Name:QF-C04 Trigger Counter Module 2>.Model:QF-C04 3>.Work 4>.Work 5>.Trigger 5>.Display:0.56" 4bit Red 6>.Work Temperature:-25~85 7>.Work Humidity:0%~95%RH 8>.Size:65*29*19mm Function: 1>.Each for time input a trigger the calculator adds one 2>.Returns 0 when press Clear button. Application: 1>.Trigger counter 2>.Industrial control 3>.Equipment inspection Note: If you select the induction module as the input, you need to select the NPN normally open type When controlled by other microcontroller signals, the low level is valid, and