GPR-H1000-1 Solar Master of G Rangeman Resin BlackG SHOCK RANGEMAN GPRH1000, in an extra rugged design, is equipped with an optical sensor to measure heart rate, a compass, altitude air pressure sensor, thermo sensor that measures temperature, and accelerometer and gyroscope to detect body movement. The new RANGEMAN is made of Bio based resin, a plant derived renewable material. Shock resistance, 200 meter water resistance, and solar assisted charging make this an exceptional timepiece.