I built mine to fit CenTech (Harbor Freight) 7-function multimeters. These are $10 normally, but HarborFreight likes to use them as one of their "loss leaders", which means if you're patient and watch sales, you can get them with a "free with any purchase" coupon!
Between that, and using free "up-cycled" junk I had laying around, this whole thing cost me exactly $0 dollars! :)
The board is from some junk chipboard furniture, cut to 7 inches wide and however tall the meters are, plus the lip. (I didn't measure that part.) The legs are each 3/4 inch wide by the same height. They are attached snugly with grabber screws at the pivot point.
They also have a hole drilled near the top with a length of scrap cat-5 wire between to act as a carrying handle and wall hanger. Interestingly, you don't have to hang it straight up and down on the wall like the picture, but can pivot it out at an angle to make the LCD's easier to read as well.
Like the other instructable, I drilled top AND front holes for the probes. (At 1/4 and 3/4 inch in from both sides).
The meters are attached with self-adhesive velcro dots so I an easily rip one or both loose when a project calls for it.
I also labelled one meter V (volts) and the other A (amps). Of course they don't always have to be used for that, but when measuring power that should help me keep the readings separate at a glance.