Equipped with mirrored Cat. 4 lenses and genuine leather side shields, the Heron Glacier delivers maximum alpine protection and remains the go-to choice for record-breaking mountaineers and ski tourers. Classic Cat. 4 glacier sunglasses featuring a vintage round silhouette, leather side shields, a removable centerpiece, shatterproof lenses, and full-mirror coating. Lightweight and highly durable Heron Glacier sunglasses are equipped for unmatched eye protection in extreme alpine conditions and high-altitude environments.