Every Chrony measures the speed of bullets, arrows, shotguns and air-pellets, paintballs, etc. from 30/fps, to 7000/fps. and within 0.5% accuracy. A Chrony chronograph completes your reloading needs at an affordable price. Just unfold (like a book), mount onto a tripod or place on a table, insert diffusers (sky-screens) and shoot in less than 2 minutes. Every Chrony is made of 20 gauge steel but weighs less than 2 1/2 lbs.: It is powered by one 9 volt alkaline battery (not included) and equipped with an extra large LCD-readout: 0.5" high when folded, it is 7 1/2" long, 4 1/2" wide and 2.75" high. Gives numbered shot velocities ( velocity stays on display until you shot again. Comes with a huge 14 1/2" x 14 1/2" triangular shooting area. Uses one 9 volt alkaline battery with 24 hours of continuous use.