This print is calibrator to hone in the G29 values of the Monoprice mini delta. It should be printed as one layer, at .2mm height, two perimeters, no infill. I'm including the STL as well as GCode, sliced in Simplify3D, within which you should only need to change the G29 line.
You can find more information about adjusting your G29 values here
I prefer using G29 P1 with C and Z values , because I don't think that P2-6 work very well if your optical sensors aren't exactly aligned. There's still a certain amount of discussion about whether it's advisable to adjust your optical sensors, so I'm not going to detail that process here, but it will probably update on the wiki, and I'll update to include a link when it does.