This part functions similar to a longer version of our 4x2x1 fence pins, but with some added features.
The pins can be adjusted to bridge two holes at a 45 degree angle, whereas the other blocks are designed to work at a 90 degree angle to the system grid.
A second feature as part of the EBS (Extension Block System) is that it can be combined with the tooth block to form a right angle bracket with holes oriented on its side face perpendicular to the tooth block.
Bolts used to combine two blocks keep the 1/4"-20 SHCP while the Stud Pins start with a 5/8"-11 thread and flare out to fit snugly into a 5/8" hole.