The blackburn 239fer front or rear light is a smart compact usb rechargeable light that acts as either a front or a rear the bright 60 lumen front amp 20 lumen rear settings will ensure passers by know exactly where you are with the push of a button the 2rsquofer can switch between a white 60 lumen front light and a red 20 lumen rear light holding the button for 2 seconds turns the light on and off and pushing the button once changes modes between white solid red solid white flash