Non-slip sandal with wholly replaceable parts

A non-slip sandal for attaching over a shoe or boot to provide traction on slippery surfaces is described. The sandal has a soleplate, upstanding sidewalls circumscribing the periphery of the soleplate, and straps attached to the sidewalls for securing the sandal over the shoe or boot. The sandal may be equipped with replaceable studs protruding from the bottom surface of the sandal for resisting slippage on the surface underneath the sandal. The replaceable studs have threaded shafts that are received by threaded nuts, which are molded into the bottom surface of the soleplate. Alternatively, the sandal may be equipped with a replaceable layer of a synthetic foam material on the bottom of the soleplate.