It's nothing fancy, made from scrap wood in my garage. Basically it's just a 1x4 on top of a 2x4, cut to the same length, one on top of the other. On the top one, I bored holes all the way through to match the diameter of the tubes, in 4 sets of 9 holes. 4 was the number of tanks I had at the time, and 9 is the number of different water tests I have on hand. You can make it bigger or smaller, more holes or less, spread out or compact, just as long as your holes are a fair distance apart (I left one vial width between each hole). After the holes were bored, I connected them with wood glue (making sure not to get it where the holes were), and a couple of screws. Then I added a handle in the very middle for convenient carrying. I don't have any pictures of it, or I'd post one.
One thing I would have done differently, is use a 1/16th" larger hole size than I did, as the wood swells up a bit when it gets wet, and sometimes some vials don't like to go in or come out easily, and I've lost a couple trying to wiggle them out. I don't remember which size I used, but basically, measure a vial, cut a hole in some scrap wood, get a nice secure fit, then add 1/16", and it should come out really well. I also would have liked to use 2 matching pieces of wood for asthetic purposes, but like I said, it was just scrap from around my garage.
In my original idea for it, I also wanted to have a storage spot for my various water tests as well, but it seemed like it would have just gotten too big and bulky, and rather pointless when I do all my testing in the same spot anyway, and it's just the vials that need to go from tank to tank to collect water.
I know I was super excited when I got it for such a steal! 