Shooting Chrony ChronographSix Different Models to Accurately Measure Your Bullet Velocity Bullet Velocity... Knowing your actual, real velocity lets you calculate your actual, real trajectory. The Shooting Chrony includes all of the electronics and sky screens for reading velocities from 30 feet per second (fps) to 7000 fps. Just set it up on a tri-pod or bench 10 feet in front of you and fire thru the center of the V rods and sky screens. The Chrony will measure the velocity with 99.5% accuracy. Standard Models have the read-out directly on the Chrony (above left). Master Models have a separate read-out and remote control unit that sits with you on your shooting bench. All Chrony models measure velocity equally well. Differences are in the features of the on-board software F-1 and F-1 Master Chrony - Gives numbered shot velocities, velocity stays on display until you shoot again, has a jack for the Chrony printer, and upgrades to any of the more sophisticated Chrony models. The F-1 is the simplest and least expensive Chrony Chronograph. Alpha and Alpha Master Chrony - All of the F-1 features PLUS 2-32 shot memory (one string). Alpha Chrony calculates high, low, average, extreme spread, and standard deviation. Retrieves and even edits individual shots and stats from memory. Beta and Beta Master Chrony - All of the Alpha features PLUS 60 shot memory (6 strings) with stats for each string. Has retrievable memory after powering down. Accessories for Your Chrony - Include a Ballistic Printer, Indoor Light Fixture and Custom Chrony Carrying Case. All Chrony Chronographs fold up for compact storage and transport.