Rotating Spanner / Schraubenschlüssel

The spanner is one of the common tools in our life. But there still are some shortcomings in the ordinary spanner, for example, its size is fixed and can not be changed flexibly. We are inspired with the camera aperture, and then the adjustable spanner is prompted. You may push and pull the modifying button with one hand during using, so as to change the size of the spanner to satisfy different nuts. Each spanner has 5 optional sizes to meet different requirement. It can both improve efficiency and save material.