Circuit knowledge

This is image of police siren circuit, this siren series can be applied in motorcycle or car. Electronic components used are 2 pcs NE555 IC as an stable multivibrators. Frequency of police sirens are controlled by IC NE555 Pin no.5.

Police Siren circuit components:

IC NEE555 = 2 pieces
2.2 KOhm Resistor = 2 pieces
Resistors 47KOhm = 1 piece
Capacitors .01 UF = 1 piece
Kapsitor 47 UF = 1 piece
Kapsitor 0.1 UF = 1 piece
Capacitors 1 uF/16V = 1 pc
Potentiometer 47 KOhm = 1 piece
Potentiometer 100 KOhm = 1 piece
Speaker = 1 piece
Micro Switch = 1 piece
Power Supply 5V - 15V