Bazzaz Z-Fi QS (ECU+Quick Shifter)

The Bazzaz Z-Fi QS is their Z-Fi unit with the addition of a Quick Shifter, hence the QS designation.  It provides you with seamless clutch-less up shifts.  The old school way to do clutchless up shifts was to roll off the throttle for a split second, which unloads the tranny, and click the next gear. 

Quick Shifters like the Z-Fi QS do that for you by sensing pressure on the shift lever when you click it and in that nano second the QS unit cuts the power to the motor, unloads the tranny, and poof, the bike shifts.

The Z-Fi QS incorporates all the features found in the standard Z-Fi. 

It does not allow for clutchless down shifts.  Only Troy Bayliss does clutchless down shifts, and nobody but him seems to know how he does it.  Some new super trick ECU's in World Superbike and MotoGP do clutchless down shifts.  Ben Spies talked about it regarding his World Superbike Championship winning Yamaha R1.