The PHYS has a smaller more lighweight case, the new PHYS models are designed for 10-year battery life. A LAP MEMORY 60 features lets you store up to 60 records in memory, each record including the date, lap time, split time, and distance covered. You can configure the the watch to emit a beep to help you maintain the pace you want. You can also input your stride lenght for automatic calculation of the distance you cover based on the number of beeps that sound. A cumulative total of distance covered is also maintained for instant display when you want it. Bands are available made of resin or cloth. Other features include an AUTO LIGHT SWITCH that illuminates the display when the wacth is angled towards the face, which is just the thing for nighttime training,DUAL TIME comes in handy during international travel, and big, easy-to-read display, and much more.