The Title Boxing Classic Personal Training Workout Interval Gym Timer is an excellent personal training timer that can be personalized for you. The rounds can be set at 2, 3, or 4 minutes, rest periods can be set at 15, 30, 45, or 60 seconds, and interval periods can be set for 0, 15, 30, 45, or 60 seconds. The timer fits easily into your gym bag for portability and ease of use! Rounds can be set for 2, 3, or 4 minutes in length. Rest periods between rounds can be set for 15, 30, 45 or 60 seconds. Interval period during rounds can be set for 0, 15, 30, 45 or 60 seconds. Multi-cadence beeps indicate round beginning and ending. A single distinct beep indicates interval period. Can be used as just a round timer, or incorporate interval workouts in your training. Fits easily in gym bag for portability. Size: 8" L x 6" W x 3" H. Timers are compatible with U.S. based, 110-volt outlets. For customers outside the U.S., an electrical converter must be used to ensure proper operation.