Vanquish Products Scale Hardware Tool Tip for 4-40 scale hardware (VPS01701, VPS01702, VPS01703, VPS01704, VPS01705, VPS01706)
Tool shaft diameter is 4mm
Tool is equivalent to a 3mm nut driver.
Hex shape on tool shaft is made to work in conjunction with standard "cross wrench".
Also compatible with Vanquish Products 1/4" Tool Adapter, VPS08430