High visibility lighting system is visible from almost anywhere in the gym and indicates work or rest periods. Allows for 2 or 3 minute work cycles, 30 second or 1 minute rest periods options, and 30 second whistle and light before the end of each round. Loud 3 second bell can be heard in the noisiest gym. Great for speed drills and also lets you vary round length. Includes a 1 year limited warranty.