Perfect Connextion Golf Swing Trainer MEDIUM/LARGE Deluxe Package With Instructional DVD. Medium &ndash; Bicep 12-14&rdquo; which is most men and some women. You Will Also Receive An Exclusive Free Bonus DVD From the Golf Lessons With O&rsquo;Leary Series With Your Order Feel the connextion of your shoulders, arms, and chest as you rotate in your backswing. Reinforce the proper right elbow position at the top of your swing; keeping the club stable. Prevent over swinging, which encourages a proper forward swing sequence. Improve your swing by creating a repeatable and sound swing, thus a "repeatable motion". Eliminates the slice swing by keeping your arms connected and in synch with your body. Prevents a short arm or chicken wing stroke.