Built to lock in on holds where other shoes give out. The Sigma is a high-performance outdoor shoe engineered for technical face climbing and overhung routes where edge support is what gets you through moves. It delivers exceptional power through a very small contact point — the kind of shoe you reach for when you're heading to a specific crag with small, demanding holds and need every advantage.

Who it's for Experienced to advanced climbers focused on outdoor sport climbing, technical face climbing, and overhung routes. Those who spend time on small-edge-dependent limestone, granite, and steep outdoor crags.

When to choose it over a more general shoe Choose the Sigma for specific outdoor sessions where edge support is the priority. If your climbing involves slabs, smearing, or friction-dependent moves, this is not the shoe — the Sigma's design actively focuses power through the toe rather than distributing it across the sole, which limits smearing performance. For those technical outdoor crags though, it is exceptional.

How it fits and feels Tighter than you'd expect — the downturn and asymmetric shape mean it runs small, so size up half a size from your usual climbing shoe size. Inside the shoe there is a pronounced hump under the toe box that positions your toes to direct all weight and power through the very tips. It takes a session or two to get comfortable with this feel, but it becomes a serious asset on demanding moves.