For auto bed leveling, if you have problems with repeatability, because of temperature swings, this may be the thing for you.The SG-90 servos is not very precise, especially not when the temperature around it varies a lot, which it does when you switch between printing PLA out in the open, and ABS inside a closed chamber. With this bracket, the arm hits a mechanical stop when extended, making repeatability way better, than if you just relied on the servo to position the arm the same place each time it extends. Retract and extend angles is 0 and ~55 degrees.