This is a derivative of the clamps that hold the Mendel Y axis bars. It holds a microswitch for the Y max or min sensor.Print, use like a pinch clamp secured between 2x M8 nuts & 2x M8 washers. Cavity points down the Y bar towards the X carriage. A microswitch is glued into the cavity, and replaces optical switches. The microswitch simply bumps into the Y Bed's foot.A microswitch with a little roller or lever out the front is best.