The pepper and salt grinders are made from solid Rubber wood fully FSC certified, finished with 8 coats of high gloss lacquer hand polished between each coat. Using a ceramic mechanism, the mill requires a clockwise motion to activate. The mills can be used for grinding either Rock Salt (Dry Salt Crystals) or Black Peppercorns. Set Includes both Salt & Pepper Mill Grinder Not to be used for sea salt, wet salt, or dried wet salt or pink peppercorns. Height including knob - 4.72" - Base: 2.75"