Serfas 110 to 1000 lm Bicycle Headlights
About Serfas - "Wherever your road leads we know cyclists seek the ultimate ride. With that in mind, Serfas is always striving to make products that reflect those wants and needs. Our 20-plus year commitment to quality, performance and customer service is reflected in our innovative products that are rider-tested and rider approved."
A lumen is a measure of the total "amount" of visible light emitted by a source. The higher the lumen rating, the brighter the light.