The Valken airsoft chronograph is a useful tool for teching, tuning and safety. Equipped with a rechargeable battery and charging cable, the compact and robust chronograph unit conveniently mounts to an included mini-tripod for use in any location. As it can be tuned to measure projectile size and weight, energy (joules), velocity and free fall, serious airsoft shooters can now use this device to adjust their guns to shoot as they desire with whatever projectiles they prefer to use!