Holder for dial gauge

Inspired by this http://www.thingiverse.com/thing:1673068 i create a new holder with only three points of support and constraint in y only on the first guide to prevent error on the distanze of the guides.
Two screw M4 to fix the dial gauge and two holes to insert the magnets like this https://www.amazon.it/dp/B003MWAIUK/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=1RGS8HT3MFUC6&coliid=I1U88ARYJRC5Y6