LED’s produce more light per watt than do incandescent bulbs; this is useful in battery powered or energy saving devices. LED’s can emit light of an intended colour without the use of colour filters that traditional lighting methods require. This is more efficient and can lower initial costs. LED’s can have a relatively long useful life. LED’s , being solid state components, are difficult to damage with external shock. LED’s are ideal for use in applications that are subject to frequent on-off cycling.