DP122-NB1 A single point doc & pin fitting.  The "Pin" bolts onto a steel or glass fin, while the "Doc" bolts onto the glass.  This fitting is most suited for glass guardrails or glass walls. DP222-NB1 A two point dock & pin fitting.  The "Pin's" bolt onto a steel or glass fin, while the "Doc's" bolt onto the glass.  This fitting is most suited for glass guardrails or glass walls. Pin & Doc Surrounding the upper floor and staircase of the Union Bank of California, the Pin & Doc system forms a striking architectural element to the office.