MK8 extruder holder for prusa I3

These are the MK8 extruder holder for prusa I3,especially used for http://www.geeetech.com/acrylic-geeetech-i3-pro-b-3d-printer-kit-p-917.html and
https://www.geeetech.com/geeetech-unassembled-prusa-i3-pro-c-dual-extruder-3d-printer-diy-p-927.html