The exposure sirus mk5 front light is a compact good looking and powerful light standing out in the busy streets the sirius directs its 550 lumens far and wide lighting the path on the road to stay safe and seen excellent side visibility and choice of solid or pulsing modes with convenient usb charging and a quick release bracket make the sirius the commuters light of choice cnc aluminium bodywork is packed with innovative patented technologies managing power and optimising brightness