Your tires are the only thing connecting you to the road or trail, and their optimal tire pressure relies on a complex mix of rider weight, riding surface, tire and rim dimensions, as well as wheel and bike design. More importantly, tire pressure can have a bigger impact on speed and comfort than frame and wheel choice combined. So, Quarq decided that whatever can be measured, can be improved upon, and that idea has come to life in the TyreWiz Air Pressure Sensor. A first in the cycling world, this sensor delivers highly accurate, real-time tire pressure data to your cycling computer or smartphone to help you make decisions that'll affect rolling resistance, traction, tire wear, and your overall comfort. Lightweight, durable, and powered by a long-lasting, user-replaceable coin cell battery, the TyreWiz provides personalized tire pressure recommendations directly to your smartphone or computer through its free-to-download TyreWiz app. This data is reported with /- 2% accuracy at 0. 1 PSI resolution, so you'll be rolling closer to your perfect PSI than ever before. It works with tube and tubeless tires, as well as tires with anti-flat sealant, and is also broadly compatible with tires that use a removable Presta-style valve core for added versatility. An IPX7 dustproof and waterproof rating gives it the protection it needs to handle uncertain weather and rough and rowdy rides, while the CR1632 battery delivers a whopping 300 hours of power, which is easy and inexpensive to replace when those 300 hours run their course.