"I ordered two of these and both were a bit over 13"L as listed. I'm not too sure about the 10"W and 7.5"H, but it still looks great :D
I would suggest getting a few pieces of driftwood, so you can choose what you want and return the rest. I got one that looked a bit like the one shown in the picture, and another one looked like a L or a J.
I used the one that looks like the one shown in the picture above and covered my 10" bubble wand with it. There are a few small holes at the top and the bubble flow looks great :D
I also liked how my piece of driftwood didn't leech any tannins...I left it in a bucket of hot water and I saw no discoloration at all :D"