An article of footwear an outer sole that houses a removable inner sole. The interchangeable nature allows different uses, appearances, and configurations. The outer sole can be used as a shoe itself (e.g. a sandal) or as the sole for other transformations. Various types of footwear elements can be inserted into/over the outer sole, allowing conversion of the footwear into a sports, formal, sandal, water, slipper, dress, ornamented shoe or other footwear.