Dial indicator on 12x8 mm square rail

This is dial indicator holder on 12mm x 8mm square rail. The dimension of the bolt holes on the block is 20x20 mm. M3x10mm bolts are used. I used this to modify FT-5 to CoreXY conversion. The bolt with 3D-printed knob can be downloaded at https://www.thingiverse.com/thing:2853001. The installation video is on 1:30 of https://youtu.be/XDcGbSpI4e8