The faster the bolt can cycle the higher rate of fire you can achieve, the QEV lets your marker cycle as fast as possible. By reducing cycle time you also save on air, by installing this QEV in your marker you can increase your shots per tank after dropping your dwell. eXTCY Paintball Markers, eNVY Paintball Markers, G1 Paintball Markers, Vibe Paintball Markers, SP1 Paintball Markers, ION Paintball Markers, ION XE Paintball Markers