Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4847369.

While I do not know the official term for this part, it is for the Urban Armor Gear case for the Microsoft Surface. A piece of plastic broke off the item, making it impossible to prop up the computer. The untested version 8 tightens the clearance and removes some plastic that was placing a small amount of pressure on the case. The plastic in question is the sloped section, along the wall, that can be filed down if needed.

Edit: Adjusted the lengths on both the "clearance" mentioned before, and the triangular "catch" to my personal tastes. During some but not all prints, the cylindrical portion of the print would fail occasionally, forcing a reprint.