I own a swing chain. In fact, it is my second since I upgraded to a heavier size. When I began using it about a year ago, my swing speed was 96 mph and would sometimes top 103. Now, my swing speed is 105 and will sometimes top 111. This is the only training device I use. I love it.
Good stuff, exgolfpro. Thanks!
How do you use it? For example, number of reps per set, time per set, etc. Also, do you prefer continuous motion or individual 'explosive' Motions?