This is a standard optical bread with 1/4''-20 threads and 1'' separation between the mounting holes. The breadboard is printed in sections of 5x5 holes that attach to each other on the sides. The holes on the top are 1/4''-20 tap holes, except the center hole, which is a through hole for mounting the breadboard or attaching stands. On the sides there are pairs of 1/4'' tap and through holes for attaching the sections to each other.

This breadboard was designed to house optics near a SERF magnetometer array, so it's intended to be non-magnetic, rigid and light-weight. Other non-magnetic components used to hold the optics are:
https://www.newport.com/f/molded-composite-optical-post-holders
https://www.newport.com/f/molded-composite-optical-mounting-posts
https://www.thingiverse.com/thing:3207906

The recommended material for this board is ABS. It's important to apply ABS slurry to the build plate prior to printing to minimize warping. The board requires post-processing with a drill press and tap.

The board dimensions are 132 mm x 132 mm x 20 mm (5.18'' x 5.18'' x 0.8'')