Muzzle velocities
Chronographs

Velocity meters are essential equipment for every organizer of airsoft events, because thanks to accurate measurement of power you can easily achieve regularity and equivalence of all airsoft replicas on the battlefield and avoid unnecessary arguments about why someone has twice as powerful gun. Be sure to state the allowed limits before the event so that players arrive at the event already prepared and don't have to change springs on the spot.

Chronographs are also useful for home gun tuners who want to have a detailed overview of the performance of an airsoft replica.