1503 Series M4 x 0.7mm Shoulder-Standoff (6-8mm OD, 10-8mm Length) - 4 Pack

This standoff provides a low-profile solution for mounting W-Wheels.  The center of the W-Wheel will be 13mm from the base of the shoulder standoff, allowing for a mere 1mm of clearance when running the W-Wheels on the goRAIL.  If you’re concerned about the overall height of the assembly, this length is a great option.