small white box
https://amzn.to/3UjgDcs

magnet wire 22awg
https://amzn.to/3vYjlut

Toroid Core,Ferrite
https://amzn.to/3Q2dKKE

Quick Connect Terminal
https://amzn.to/3vY9dSy

150 ohm Resistor
https://amzn.to/3JHCJiR

D304X transistor
https://amzn.to/3vNAneW

10k ohm Potentiometer 10-Turn
https://amzn.to/3xG0btS

on/off switch
https://amzn.to/3U5BL4m

on/off button
https://amzn.to/3UmOUrt

piezo disc
https://amzn.to/3UlI717

ac/dc adapter 5v 2a
https://amzn.to/3Ujis9i