The Competition Electronics ProChrono DLX Chronograph with Built-In Bluetooth is a next generation chronograph with proven technology and design. The ProChrono DLX Chronograph with Built-In Bluetooth operates off of one 9-volt alkaline battery, which will need to be purchased separately. Great for use across shooting sports including firearms, archery, airguns, and even paint ball. 2 year warranty against defects in material and workmanship, and a 1/2 price repair guarantee Operates off an Alkaline 9-volt battery power for 20+ hours of operation (not included) Velocity Range: 20 – 9,999 feet per second Memory Capacity: Up to 9 strings of up to 99 shots each Minimum Time Between Shots: 500 mSec Shot Timing Resolution: 31 nSec (8000 counts @ 4,000fps) Crystal Controlled Accuracy: +/-.5% of measured velocity or better The ProChrono DLX Chronograph features on-board Bluetooth connectivity, and more options are available with FREE apps for iOS, Android, Kindle, PC, and Mac. A built in full featured operating system has multiple shot string memory and statistics, and a sensing system is compatible with a wide variety of light conditions and projectiles. The ProChrono DLX Chronograph has a faster internal shot clock for improved accuracy to +/- .5% or better. Made in the USA.