Caldwell G2 Ballistic Precision Chronograph with Tripod and Rechargeable Battery for Shooting Indoor and Outdoor MPS/FPS Readings SPECS: 18 sensor spacing for maximum accuracy and each unit is factory calibrated to within +/-0.25% accuracy and measures from 5 to 9,999 FPS EASE OF USE: Front LED display shows velocity information, the inverted LED light panels make shooting are perfect for shooting indoors and the app displays velocity, logs data, notes, weather conditions and exports via SMS or email VERSATILITY: Meters per Second (MPS) or Feet per Second (FPS) reading and is ideal for firearms, archery, airgun and paintball CONVENIENT: Features a rechargeable Li-Ion battery, hinged support bars for easy disassembly and storage and a high-quality storage case for easy transport COMPATIBLE: Works with the following that have Bluetooth 4.0 or newer: iPhone, iPad, iPod Touch, Android 2.1 or newer and Kindle Fire Tablets