The main thing that is appealing to me is the length of the shoe, allowing for measurement over a larger gap.
Secondarily is that it's profile allows it to be laid on the side for horizontal measurement.
Most of the height gauge products I've seen have narrow feet, or have a measuring blade that protrudes only a short distance from the device.
The closest thing I've seen is the iGaging Snap Check, but I was wondering if anyone knew of other, similar devices?