Offers a Degree of Precision Unlike Any Other Chrono on the Market The LabRadar Doppler Chronograph Lite provides handloaders with data on the velocity of their handloads with a degree of accuracy and ease of use not found on traditional chronographs. not available to the consumer market until now. That's because, unlike your dad's chronograph that uses a pair of photoelectric sensors, the LabRadar Doppler Chronograph Lite works uses radar to measure the velocity of the projectile coming from your rifle, pistol, or shotgun - even works on airgun pellets and arrows. The LabRadar unit sits next to the shooter, so you've got easy access to the controls, and points to Mfg: Labradar