LiftMaster Limit Switch Kit | LIF-K75-50189 This is a replacement Limit Switch Kit. Check the manual or replacement parts diagram for specific part information before ordering to ensure compatibility. Genuine LiftMaster replacement part. ALSO KNOWN AS LiftMaster Q166, LiftMaster Q055, LiftMaster Q165. COMPATIBILITY This part is compatible with various LiftMaster Swing Gate Perimeter Access Systems.