What separates Rocket Science Sports water bottle from the rest is its unique aerodynamic design - modeled after the golf ball to minimize drag while cycling. The majority of drag associated with water bottles results from the separation of airflow causing what's known as pressure drag. Air flowing past a traditional smooth exterior water bottle separates quickly resulting in a high pressure drag. However, with this dimpled water bottle, airflow separation is delayed. This results in a smaller airflow separation region when compared to traditional water bottle designs. The dimples actually add more kinetic energy to the airflow forcing it to remain attached longer - ultimately reducing pressure drag. Bottle holds up to 20oz of your favorite beverage. ISM Adamo Quick Draw system works great with these bottles