Size Guide: Medium size fit Inspired by vintage Revo style, Watson's flattering rectangle shape features a classic keyhole bridge and unique metal detailing. It reminds us that high-performing design is timeless. Watson's lenses are made of high contrast crystal with Revo's signature NASA-based polarized lens technology for unparalleled visual clarity and protection. DETAILS Revo high-contrast polarized Crystal lenses Featuring an innovative new process that encapsulates Revo NASA lens technology within two layers of glass Measurements 51-21-145 Lens Height 43.2 mm 6-base lens technology A flatter profile, temple to temple Spring hinge For a flexible, secure fit Elastomeric temple tips Slip-reducing rubber provides a more secure fit Revo Light Management System™ Filters harmful UV, HEV, and Blue Light Digital Device-friendly Reduces glare and enhances clarity of digital screens SIMILAR STYLES Similar fit in round: Python III