52-17-140. Made of silver or gold plated titanium, this is the most lightweight frame in the collection. Elegant and unisex, the round thin-silhouetted profile is complemented with hits of enamel on the corners and bridge. The frame is named after famed explorer and mountaineer Bill Tilman. 100% pure titanium plated in 12k silver, 18k gold, or 24k gold combined with matching titanium temples and a hidden spring hinge. Individually numbered and handmade in Japan from the world’s finest artisanal craftsmen.