I like the keen concept , but they be cheaply build and unacceptable as a beach sandal . I have the black model and they have turn a dark purple . the sun or salt water may have cause the change . I wear they everyday during my Culebra vacation . the shoe be not sturdy enough to use on a gravel beach . when I hike a rocky path , I have to be careful or I would twist my ankle . my companion wear Teva sandal they prove to be a better casual sandal .