I bought this to use with a bass combo - a Genz Benz contour. I wanted to raise the combo up a little, as when it's on the floor, most of the sound it produces is directed at the back of my knees. This is a perfect solution and is surprisingly stable. It folds up neatly and seems well made, although mine initially came with one of the plastic feet missing. Thomann quickly rectified this, but spare feet cost about £3 for a set, so it might be worth getting a spare set, just in case.
Quiklok does a very similar product to this, but I couldn't justify the expense. This seems to do the same job, but for a much more affordable price.