Ultremo HT tubular is hand glued and sewn together to Schwalbe"s exacting specifications. The Ultremo HT uses a 300 TPI casing so it"s very supple. The Racestar Triple Compound rubber is class leading in multiple tread compound technology.Schwalbe is a market leader in bicycle tire design and manufacture. Innovative designs and market specialization make their tires stand out both in quality and performance.