PACT Model 1 XP IR Chronograph System 22 11 4 in. These Shooting Accessories by PACT use radar guns with a built-in light to track the shots to ensure the shooter is seeing the sight picture. The radar gun works by reflecting a small percentage of the shot velocity back to the shooter via the IR Beam. Therefore the PACT Model 1 XP IR Chronograph System w/ Skyscreen includes a mounting bracket and hardware for a TV or computer screen display. You can even set this up in a sled-mounted configuration. However the Model 1 XP does not include the professional grade Chronograph accessories (Such as the PACT Chronograph XL or XL Chronograph). You will however receive the radar gun's velocity reading the average velocity standard deviation extreme spread and standard and average deviation calculated by the radar gun. This is invaluable information if you are looking to improve shooting mechanics or performance. For a top-of-the-line shooting accessory look to the PACT Model 1 XP Infrared Chronograph System. Specifications for PACT Model 1 XP IR Chronograph System: Manufacturer: PACT Color: White/Blue Included Accessories: Mounting Tools Length: 22 in Width: 11 in Height: 4 in Package Contents: PACT Model 1 XP IR Chronograph System PACT M1XP-IR: Model 1 XP IR Chronograph System 22 11 4 in