These bushing holders will allow you to mount the SDP/SI bronze or acetal bushings holders to the Pillow Block X-ends or a Y-axis plate.8mm or 10mm SDP bushings are compatible which can be found here: https://sdp-si.com/eStore/Direct.asp?GroupID=469.These holders will mount on either the ACME Pillow Block x-ends: http://www.thingiverse.com/thing:22760 or the standard Pillow Block x-ends: http://www.thingiverse.com/thing:18399 They can also be mounted to the Y-axis plate: http://www.lulzbot.com/en/127-y-axis-plate.html