The term LED refers to Light Emitting Diode which is an increasingly popular choice for a variety of light sources.
How efficient is LED?
LEDs emit more light per watt than incandescent lights.
Is there an on / off time?
LEDs light up to full strength very quickly.
Are there any cycling disadvantages?
LEDs are ideal for uses where frequently switching on/off is required unlike fluorescent lamps that fail faster when cycled often, or HID lamps that require a long time before restarting.
Is there a failure warning?
LEDs generally fail by dimming over time, rather than the abrupt failure of incandescent bulbs.
What is the general lifetime?
LEDs can have a relatively long useful life. Some can even last to an estimated 35,000 to 50,000 hours of useful life, though time to complete failure may be longer.
Are they shock resistant?
LEDs, being solid state components, are difficult to damage with external shock, unlike fluorescent and incandescent bulbs, which are fragile. This makes them perfect for mobile applications like 4x4, trucks and torches.