Garmin Forerunner 235 Activity Tracker

Wrist Based Heart Rate: Forerunner 235 utilizes Garmin’s very own wrist based heart rate sensor that tracks 24/7
Larger Screen: A 44 percent larger screen than the 225 but the same physical size, Battery Life: 12 weeks in watch mode and 12 hours in training mode
Audio Prompts: Receive audio prompts from your connected smartphone that include laps and lap times
Smart Notifications: See incoming email, text messages, call alerts, calendar reminders and more from your compatible smartphone
Display Size: WxH – 1.23 inch (31.1 mm) diameter, Physical Dimensions: 1.77 inch x 1.77 inch x 0.46 inch (45 x 45 x 11.7 mm)