The Heater F-35 Black Cup Face Titanium Golf Driver (TaylorMade RocketBallz RBZ clone) uses a pre-installed 5-gram weight. The scalloped crown produces a very low center of gravity, creating a higher launch angle with a low spin rate for optimal distance! The Heater F-35 Black 460cc driver uses a new "cup-face" construction, where part of the faceplate is incorporated into the sole, crown and skirt area of the head. This pushes the weld back away from the face. By moving the weld further back, the areas around the perimeter could be made thinner and deflect more, thus producing a higher ball speed to areas other than the center of the face compared to traditional welding techniques. Even when you miss-hit the ball, drivers with cup-face technology provides that extra spring-like effect for longer, straighter drives. The F-35 has a distinct black color on top of the head for reducing glare. Compare this to the TaylorMade RBZ and see why this is such a fantastic buy!