With 270 degrees of visibility the Flare I light from Bontrager will ensure that you're seen from all angles through the dusk & into the night. The light is sealed effectively against the weather with a rubber gasket so you can rest assured the three LEDs will be clearly visible from up to 600 meters away even in the rain. A solid Bontrager mount with rotational position adjustment secures the light to the bike, soft durable rubber wraps round the seat post with a quick connect lever to allow removal of the light while leaving the mount in place. For those that still appreciate easily replaceable batteries the Flare takes two of the AAA type & the first set comes included in the box. As with most disposable battery lights the LEDs will steadily get dimmer as the battery voltage reduces rather than just cutting out immediately, for best results replace the batteries around the suggested run time outlined below.