These are a stunningly good bike light! They large size, plus the 18 LED's make them very visible. Battery life is good, and they're bright enough to use as a (red) torch if that's your thing.
It does lack the standard bicycle mounting
attachments. I've seen several ways to mount them, ranging from bent
coat hangers through clear themoplastic to the bolt-on ones I prefer.
I drill a couple of holes in the back and bolt strips of aluminium to
the light. These hook over or onto the bike in the traditional way. On
one bike I have simply removed the 3mm screw that holds the rear cover
on and used a longer bolt to hold the light onto a plate brazed to the
bike. That's the advantage of building the bike too... The mount on
Tall Bike Two shows what I usually do, with the back plate of the
light in place - albeit in this case the custom bike got a custom
mount.
Available from Jaycar Electronics, Giant LED light, part ST-3039, $AUS28.00.