Quantity   Component name
10 × Through-hole resistors (see schematics) 1K, 2.2K, 20K, 100K
2 × 2N3904 transistors Any NPN type transistors will work
10 × Electrolytic capacitors 100uF, 22uF, other values are nice to have
2 × LEDs green or yellow work well for a firefly
1 × 555 timer