The Cateye Opticube is a handlebar-mounting bicycle light that uses a white LED bulb. The unit takes three AAA batteries and the company claims these will last up to 60 hours. There are three settings to the light, with a bright, a midlevel and a blinker light. The Opticube is made to go onto the handlebar with no tools needed. Cateye equips the light with a Dropout lock mechanism so you may remove the light from the mount when leaving the bicycle locked up.
Unscrew the back battery housing panel and insert the three AAA batteries into the housing. Screw the panel back on and undo the ratchet strap completely.
Place the Opticube onto the centre of the handlebars - to the left or right of the stem. Bring the strap under the bars and marry the two strap ends together so the end sticks out of the black ratchet locking device. Pull and down on the ratchet to tighten the strap thus securing the light to the handlebars.
Press the rear Dropout button to pop the front of the light free. Pull up and out to remove the light from the mount, or back and down to snap it back onto the mount.
Push the switch on the back of the Opticube to the first setting for the bright light, the middle for the midlevel light and third position for the blinker. Push it all the way to the left to turn it off.