90° Angle bracket for 20x20 aluminium profile, B-type nut 6

This is another 90° angle bracket for 20x20 aluminium profile (B-type nut6).
I have printed in PETG with slightly support as shown in the picture 3. Different orientation may also work fine.
Two of the M4 T-nuts are needed and bolts M4x8mm

2016-10-01: An update was required in area of the t-nuts cutouts, for better tightness.(RevA)