Ian White wrote:

Starting from the top and working downwards, the laser/level unit itself
is OK. It throws horizontal and/or vertical lines that are good enough
for most indoor uses, and I've used the spot for outdoor layout work at
ranges up to about 20m in sunlight.

I use a large piece of reflective sheeting to shine the spot on.
It is visible in bright sunlight for 30 metres, which is as far
as I've needed to measure.