NE555 Pulse Module Frequency Duty Cycle Adjustable Square Signal Generator ~（

ITEM NAME:NE555 Pulse Module Frequency Duty Cycle Adjustable Square Signal Generator ~（.Main chip: NE555;. 1 x NE555 Pulse Frequency Duty Cycle Adjustable Module. Generate adjustable pulse for MCU. Output with LED indication(low level ,LED will on; high level,LED will off;low frequency, the LED flashes);.