Calyx™ - PMO’s First Step into Footwear

Purple Mountain Observatory marks a new chapter with the debut of its first footwear silhouette: the Calyx™, created in collaboration with Vibram.

Born from months of experimentation, the Calyx™ channels PMO’s outdoor design ethos into a single, sculptural form. At its core is Vibram’s advanced StratX formula, a breakthrough process that allows the upper to be seamlessly moulded from a single sheet of specialised rubber, removing the need for stitching or multiple layers. The result is a smooth, waterproof shell that’s as striking as it is functional.

Beneath, the shoe is anchored by the Vibram Grivola outsole, built with the brand’s renowned Megagrip compound for lightweight traction, long-term durability and all-weather confidence. 

Launched 22 August 2025, the Calyx™ is available online and through select retailers.

Follow @purple_mountain_observatory and @vibramconnect for a closer look at the journey from concept to creation, and for the first chance to step into PMO’s next evolution.