Pololu Universal Aluminum Mounting Hub for 3mm Shaft 2-56 Holes (2-Pack)

These universal mounting hubs are designed to work with most 3mm shafts, including round shafts, ?D? shafts, and Tamiya?s 3mm hexagonal shafts. Each hub has four mounting holes for 2-56 screws (not included), letting you mount custom wheels or mechanisms to your motors. 4-40 hex set screws (one included for each hub) allow secure coupling of shaft to hub. A 0.05" hex wrench (often the smallest size in SAE Allen wrench sets) is included for use with the set screws.