A clamp on Z Height adjuster for use with my Rock Solid mounts. You need: 2x M3x25 Bolts 2x M3 nuts 2x M3 washers 1x small coil spring (nominal 3mm ID) Notch in the dial so you can quickly see if Z height has shifted, or calculate no. of turns. With M3 bolts 1 turn is 0.5mm which is convenient.This one is 0.3mm layer height, 20% infill, no supports. Ream out the top of the knob with a 5.5mm drill bit for the first 1/2 to 2/3rds. This will make sure that your cap head M3 bolt push fits solidly in. If yours is a little loose (or if you drilled too much) a drop of superglue will be adequate.