The A4 wallet (2014) is minimal wallet platform designed with my partners Matthew Hall and Brian Johnson at Obstructures. It’s development was funded by a campaign on Kickstarter, and its operation is based on our patented rolling o-ring hinge.
The design of the A4 was an iterative development on our previous A3 model, and also involved a numeric model that located the rings for an optimal balance between easy opening and secure closing.
The design of the A4 was an iterative development on our previous A3 model, and also involved a numeric model that located the rings for an optimal balance between easy opening and secure closing.