The M91ti is set in a fashionable titanium case with and adjustable safety clasp. Like the M61, this is a great option for the individual seeking complete guidance and feedback, all in a stylish watch. The OwnIndex™ will determine your fitness level within a 5 minutes, while you lay on your bed, a great tool for tracking your fitness improvements. OwnCal™ counts the calories and fat that you burn based on your effort level, not the treadmills. And OwnZone Advanced™ takes the guess work out of finding your personalized target zone. The M91ti will determine 1 of 3 preset target zones based on how your body feels for that specific day. The M91ti is truly the smart HRM.