That looks like the same stuff, but Scamp
only stocks it in one width/depth (at least as shown in your link).
The Trimlok page has a number of different widths and depths, and shows how to measure it. (That said, they only sell really long rolls; but with a part number one could probably source it from a retailer; Trimlok is the manufacturer.)
What I don't know is whether Scamp's piece is the correct size; 3/8" inside width sounds like it may be a bit more than optimal for a U-haul
seam. Of course it would be handy if it did just happen to be the correct size.