Reflex Hammer (Babinski / Queen Square)

Yet more reflex hammers, this time the Babinski or collapsible Queen Square type.
Requires an M3x18 mm screw and nut (nylon lock nut preferable) to hold the head on the handle
The collapsible handle has optional parts to help retain it in the closed position - a 6 mm diameter magnet (any thickness) and an M3 screw (anything that approximate size will work, as long as it is magnetic).