Black Mustang Shift Knob Boot Retainer/Adapter For Manual Shifter Lever M12x1.25 Installs in seconds! Keep your shift lever looking clean with this piece. Does NOT fit "2010+ Shelby GT500" or Mustangs with "401a interior". Check our other items for boot adapters to fit other Mustangs Designed to work specifically with ALL Sickspeed brand shift knobs.