The lazer sport grace ii lifebeam helmet takes the compact design of the award winning grace helmet and integrates a lifebeam sensor within the existing head band to monitor your pulse rate and calories burnt the sensor communicates with a processing unit built into the back of the helmet that can then transmit data to most modern communication devices with ant or bluetooth removing the need for a chest strap this ever popular helmet also has all the top features and great venting of a pro he