The StairMaster TwistLock is an expensive pair of dumbbells with an excellent grip, and very fast and easy weight adjustment.
Pro Great if you really need to change weights fast
The StairMaster TwistLock dumbbells are a great (but expensive) option if changing weights as fast as possible is the most important thing. These dumbbells use their handles as the primary mechanism for adjusting weight. Just place the dumbbell in it's tray and twist the handle. It's a good time saver for very fast paced conditioning workouts. The mechanism only works when the dumbbells are docked in their trays, so you don't have to worry about anything going wrong in the middle of your workout.