A compact 4 mm precision screwdriver is an essential tool for technicians, hobbyists, and anyone working with delicate electronics or small mechanical assemblies. 

The design includes a swivel end cap, allowing the user to apply steady downward pressure with one finger while rotating the shaft with the other hand. 

There is also a small room within the handle to store commonly used 4 mm bits 2 or 3 pcs. 

A replaceable head with magnetic inserts further enhances usability.  

Be careful when twisting the endcap the first time to break the fused filament, bending would easily break the end.

Printed with PCTG for better durability, PLA break's to easy. The top bit end has a pause for inserting a 5mm magnet/rod up to about 7mm thick.