While many companies are making their lights smaller and smaller (think Blackburn's Flea and RSP's own Mico Flexilite), the Night Flare is a reassuringly chunky affair which, at over 12cm long and with five LEDs, is hard to miss from behind.
Side visibility isn't quite so good – the LEDs are visible from the side, but because none of them is angled sideways, they're brightest from behind – but still better than many other rear lights on the market.
There are four modes – constant, fast flash, slow flash and cycle – which are operated by an easy-to-find button on the back of the light and powered by two AAA batteries. The Night Burst seems a lot brighter when flashing than when constant.
The supplied seatpost bracket allows you to mount the light either vertically or horizontally, but side visibility is definitely better when it's upright. You need a screwdriver to fix the bracket to the seatpost; watch out because the soft plastic screw deforms easily.