This is the “basic surface” of the gyroid triply periodic minimal surface. Eight of them connect together to form the gyroid “unit cell.” Unit cells repeat infinitely in all three directions.
See here for video: https://youtu.be/xWxGIVsSbfc
The ways in which the basic surfaces connect together to form unit cells can be a bit mindboggling. This construction kit can help gain a better understanding of gyroid structure, which is especially helpful when designing more complex gyroid-based shapes and surfaces.
The holes accept 1/8” x 1/16” cylindrical magnets. Magnets on the same edge need to be inserted with polarity in opposite directions, and this must be consistent across all surfaces.
See here for a similar "Snap-Together Gyroid Construction Kit": https://thangs.com/mythangs/file/66429