Quantity   Component name
1 × Cheap multimeter or meter you don't mind opening up
1 × LEDs of any color
1 × Resistors for limiting the current for the LEDs
1 × Capacitor adjust for how long you want the drive the transistor
1 × transistor for switching the leds on/off
1 × Another resistor used for the base of the transistor
1 × Momentary switch Normally open in this case