Durability is a Sterling hallmark, so the Phenom is constructed to live up to this expectation. Using our higher denier sheath structure, and thermodynamically balanced performance cores, the Phenom is built to last +and perform. Featuring a 10.3 mm diameter, this rope hits the sweet spot for handling and gear compatibility. The Phenom is ideal for top rope belays outside, and top rope or lead climbing in today's modern, high-traffic gyms.