Check the listing for details. NE555 pulse frequency duty cycle adjustable module square wave signal generator. Color: red, Condition: New. Listed at 5.92 USD. Performance: 1.Input Voltage: 5V-15VDC. when power supply is 5V , the output current can be 15MA around;when 12V power supply, the output current can 35MA around; 2.Input current: >=100MA; 3.Output amplitude: 4.2V V-PP to 11.4V V-PP. (Different input voltage, the output amplitude will be different) 4.Maximum output current: >=15MA (5V power supply, V-PP greater than 50%), >=35MA (12V power supply, V-PP greater than 50%) 4.Output with LED indication(low level ,LED will on; high level,LED will off;low frequency, the LED flashes); 5.The output requency range is selectable: LF file: 1Hz ~ 50Hz IF file: 50Hz ~ 1kHz High-frequency file: 1KHz ~ 10kHz HF file: 10kHz ~ 200kHz 5.Cycle T=0.7 (RA+2RB) C (RA, RB for 0-10K adjustable); Low frequency:C=100UF; Intermediate frequency:C=1UF; M-H frequency: C=0.1UF; High frequency: C=0.001UF, Quantity: 1 piece Note: Before changing the frequency, please power off