Map Lights

Most LEDs actually can be directly dimmable by reducing the amount of voltage to them - something usually done with a rheostat (i.e. variable resistor). It mostly depends on how the LEDs are constructed. If they have independent controllers in the buld, then a dimmer rheostat may not work, but if they're just wired to voltage with a small resistor in the bulb to control current, they should be dimmable....