51-19-142. A metal variation of the classic "P3" shape, with state of the art technical attributes. Highly intricate multi-dimensional laser etching applied to the titanium, with high quality enamel insets. 100% pure titanium plated in 12k silver or 24k gold combined with Japanese cotton-based acetate temple tips and a hidden spring hinge. Individually numbered and handmade in Japan from the world’s finest artisanal craftsmen.