This kit comes with all the components and schematic needed to complete the circuit. The kits is a very easy unit to assemble and could be used in many different ways! The Kit can be powered by 5 Volts DC to 12 Volts DC. A 9 Volt DC battery Clip is included with the kit for easy 9 Volt DC access. *** Speakers not included in the kit *** An 8 ohms speaker is best to use for this kit.