STEPPER MOTOR (SECONDARY AIR VALVE IDLE)
GENUINE TRIUMPH PART
FITS THE FOLLOWING BIKES:
DAYTONA 595 / 955i
SPEED 4
SPEED TRIPLE 885 / 955 TO VIN 141871
ST 955i  VIN 141872 - 210444
SPRINT FROM VIN 139277
MAY FIT OTHER MODELS ALSO 

IF YOUR BIKE IS RUNNING RICH WITH POOR IDLING OR WONT REV OUT
THEN ITS ODDS ON YOU HAVE A FAULTY STEPPER MOTOR
THIS REGULATES ADDITIONAL AIR INTO THE INLET DUCTS VIA THE AIR BOX
COMMON FAULT ON THESE OTHERWISE EXCELLENT BIKES