These are the First Curved Latches for the RoboRio! Only a 1/8" Bolt can fit the hole with a 5/16" Head *all inch measures are mentioned as the diameter Now these pieces are not copies. They were made and designed by the L&N STEMPunks. If you have any trouble with the piece not working, place a comment and we will try to get in contact with you within a couple of days. Thank you and Go Gryphons!Prepare and Print!