Posted: 31/01/2014 at 18:26
I think he means 40 cm! Don't know why people keep working in millimeters.
1 meter is 100 centimeters is 1000 millimeters, much easier to work in meters and centimeters than faffing around with millimeters, which are only good for things like screws etc.
My OH made me raised beds out of scaffolding boards, 250 x 100 x 40 cm! They are made from very long lasting wood and can take all weathers.