The Two-Fold Skateboard is a regular skateboard with a pair of flush mounted cabinet hinges underneath which allow it to basically fold in half for easy transporting. Designed by Northwards Design Studio, I would have to question it’s usability unless there were some super secure way to lock the hinges into place when riding the skateboard (perhaps a simple deadbolt type lock would do the trick?).
Universal Principles of Design, Revised and Updated: 125 Ways to Enhance Usability, Influence Perception, Increase Appeal, Make Better Design Decisions, and Teach through Design
OMOTON 2.5D Round Edge 9H Tempered Glass Anti-Scratch Screen Protector for iPhone SE/ 5S/ 5C/ 5 - Clear (2 Pack)