This allows you to attached the http://www.thingiverse.com/thing:958 printruder I by zaggo and allows you to attached it to the mendel. Note that this basically replaces the insulator retainer.I really like the printruder Version 1, so I'm using it for my mendel's.There are 3 sets of bolt boles in the part. The big holes attach to the x axis frame. The inner small holes that in line with them attach to the base plate part. The set of bolts that at a right angle to the other 2 pairs are for you to attach the washer that keeps the insulator attached. Like everyone on earth outside of the uni of bath, I can't get acrolite to keep the insulator attached.Enjoy!The machine owned by the perth artifactory hackerspace at www.artifactory.org uses this mechanism.