Momentus Indoor Driver with Training Grip Includes FREE instructional DVD featuring Fred Funk, 7-time PGA TOUR Driving Accuracy Leader The Indoor Driver features the patented shaft-weighting technology of the #1 selling Momentus Swing Trainer. Designed to be swung at home to build the correct golf swing fundamentals to drive the ball longer and straighter The perfect training club to use each day in the convenience of your home. 30" long and 50 oz.