The RCBS AmmoMaster chronograph measures 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 that fits through the skyscreens (which are the upright structures in the image). TShooting Chrony chronographs measure speed (feet per second and meters per second) from 70 fps to 7,000 fps. RCBS AmmoMaster chronograph Records velocity of any projectile from 70 fps to 7,000 fps High, low and average data-string velocity readings Extreme spread and standard deviation data-string calculations Reads in feet per second (fps) or meters per second (mps) Low-battery indicator Full string indication 10-string max stored in memory 10-shot velocity measurements per string Detachable display unit with 20-ft cord Unit attaches to camera tripod (not included) 86 sq. in. of available shooting area under the sky screens 10 MHz clock speed Assembly required Uses a 9V battery (not included) Uniquely shaped chronograph will help you determine how fast you're shooting. This will be helpful for determining velocities of firearms, airguns and airsoft guns. Includes a very helpful and detailed owner's manual.