LEDs last considerably longer than typical fluorescent or incandescent lighting. LEDs rarely burn out like traditional lighting, but rather gradually decrease in light output over time. Their "life span" is defined as the time it takes until 70% of initial light output is reached, often 50,000 hours. Resistant to vibration and thermal shocks, LEDs perform extremely well with frequent on-off cycling. They have low heat output and are low voltage, making them energy saving and very cost efficient.