Quantity   Component name
1 × 2n7000 NMOSFET https://www.utsource.net/sch/2N7000
1 × Resistor. (10kΩ, 6.8kΩ, 2.5kΩ, 1.5kΩ)
1 × Capacitor. (100µF,1000µF)
1 × Speaker. (8Ω and 1W)
1 × Jack. (3.5mm)
1 × Battery. (9V)