Coach AJ reviews the Halo Swim Trainer.  The basic premise of this trainer is to focus on the 'high elbow catch' part of your stroke along with race-pace tempo with the use of a metronome.

Improving your high elbow catch with the Halo Swim Trainer is accomplished by using a template.  If you do the drill incorrectly, you bend the template with your arms allowing instant feedback on this part of your stroke.

The Halo Swim Trainer is not a replacement for actual swimming, you still have to do that yourself!  But this trainer will allow you to focus on certain elements of your stroke for possible improvement.