LightForce is without peer in output and performance. Superior efficiency is key to LightForces legendary light output and quality. LightForce gives you the choice to tune your light output specification by various bulb options! Bulbs used in LightForce lights have been carefully selected to ensure maximum performance and durability. This is done by measuring and qualifying the efficiency in converting WATTS into CANDLEPOWER. This combined with the superior LightForce reflector is what creates the light output that has made LightForce famous. For the technically minded! The bulb filament size and shape combined with the reflector design determine the concentration of a focused beam. The shape of the filament will determine the type of beam, e.g. a vertical filament (VF) bulb will give a circular spot beam, While the horizontal filament (HF) will give a slightly oval spot.