There are two types of solid wall "Dry Stone Walling" and "Rough Dry Stone Walling". The difference between the two being that the Rough version is slightly worn down with varying heights and missing blocks.
Rough Dry Stone Wall
Dry Stone WallThe wall sections are 150mm long Approx~ 17mm tall, 10mm wide at base (Rough version has a lower height varying from about 13mm to 17mm tall)
The sections dont need to be painted as they are pre-coloured, but a quick dry-brush improves them tremendously.
There is also a strip of flexible "stone" material which you can use to form into any shape, is approximately 4 foot long and about 10/11mm tall - this is very cheap and is useful for filling in complex shape areas with a low stone wall. It's rather cheap & cheerful but its hard to go wrong for £1.25p.