For play requiring lower velocity settings, it may be necessary to utilize the included Air Volume Spacer. 1) Follow Unloading Your Marker on page 10 and Air/CO2 Cylinder Removal instructions on page 16 of your Crossover Manual. 2) Loosen and remove rear end cap. 3) Snap Air Volume Valve Spacer securely onto shaft of air valve (Valve End Cap). 4) Reassemble rear end cap. 5) Adjust regulator pressure to achieve desired velocity.