Shooting Chrony chronographs measure the velocity of almost any projectile, including pellets, steel BBs, plastic and metal airsoft BBs, bullets, shotgun pellets and slugs, arrows, bolts, darts, paintballs and just about any other projectile. Shooting Chrony chronographs measure speed (feet per second and meters per second) from 30 fps to 7,000 fps with more than 99.5% accuracy. F-1 CHRONY - The very first model and still the most popular. Provides numbered shots and velocities. All Chrony models are powered by a single 9V battery and can be easily attached to a 1/4"-20 tpi camera tripod for fast, easy set up. The Chrony is simple to use, just unfold the box, set the diffusers in place if needed, turn on the switch and start shooting.