Purple Mountain Observatory's Calyx is what happens when technical innovation goes off the beaten path. Developed with Vibram, it pairs a waterproof slip-on upper with serious all-terrain grip underfoot. Weather-ready and adventure-hungry, it's the kind of lightweight shoe that's always plotting its next detour. Vibram Strat X Waterproof Upper Slip On Heel Pull Tag Vibram Megagrip Grivola Rubber Sole Debossed Branding Style Code: CALYX002-BLK