http://www.lidl.co.uk/gb/home.nsf/pa...it_Level_Ruler

Just bought one of these for the spirit levels in tiling. Don't
bother.

A mystery that one of you may be able to explain is the purpose of the
cutouts on the ruler. They are obviously meant to be highly useful and
vital.

Starting from the LH side there are 4 holes in increasing diameter
marked with a symbol like a small o with a foward slash through it,
and numbers 6.8.10.and 12.
Drill diameters?

Next is a horizontal diamond with " 6.5*6.5" on it.

Next is a triangle with " 8.7" on it.

Next is a flattened sphere,(can't remember what its called), with
"10*16" on it.

*******************************
At the other end of the ruler are three holes marked with this o
foward slash and 5. They are marked as 72mm apart.

The packaging shows these holes relate to some piece of equipment in
the form of a white triangular wedge shaped thing with three
depressions and holes in the bottom of the depressions. The three
holes coincide exactly with the holes in the depressions. Wifey says
it's a triple block of continental 2 pin electrical sockets.

So the three holes in the ruler coincide with the holes in a triple
continental socket, viewed vertically.

I face sleepless nights unless someone can explain at least 4 of these
terrifying mysteries to me.