Fold-up design for easy storage and safety - compact design after holding up allows users to easily keep the hex key set into their pockets or bags without taking up too much space + keeps hex keys in one bunch to prevent misplacement, and also enhances overall covenience since all the different hex keys are bunched up together 
When having to switch between different hey keys, users can easily switch to a different one for use without much hassle
Sizes of hex keys (7 pieces in one bunch) 
2 mm
2.5 mm
3 mm
4 mm
5 mm
6 mm
8 mm