High-sensitivity SiRFstarIII architecture Communication between system devices via ANT protocol Weight: 77 grams Display: 33mm(w) x 20.3mm(h) Physical size: 53.3(w) x 17.8(h) x 68.6(d) mm Lap memory: 1,000 laps Battery: rechargeable internal lithium ion Battery life: 10 hours (typical use) Waterproof: IEC 60529 IPX7 standards (submersible in one metre of water for up to 30 minutes) Alerts: time, distance, pace and heart rate High-sensitivity SiRFstarIII architecture Communication between system devices via ANT protocol Weight: 77 grams Display: 33mm(w) x 20.3mm(h) Physical size: 53.3(w) x 17.8(h) x 68.6(d) mm Lap memory: 1,000 laps Battery: rechargeable internal lithium ion Battery life: 10 hours (typical use) Waterproof: IEC 60529 IPX7 standards (submersible in one metre of water for up to 30 minutes) Alerts: time, distance, pace and heart rate Form meets function with Garmin's next-generation, sleek and stylish line of personal trainers. The Forerunner 305 combines all of the popular features found in the 301 along with a high-sensitivity GPS receiver, new courses feature and robust ANT wireless heart rate monitor for optimal performance. Designed for athletes of all levels, this running partner and personal trainer continuously monitors your speed, distance, pace and calories burned so you can train more effectively. It tracks your every move with a super-sensitive GPS that even works on tree-covered trails and near tall buildings. Receive a detailed post-workout analysis on the PC with included Garmin Training Center software.