The OT Vertical bi-cylindrical friction attachment is suitable for use with partial dentures and combination cases as well as bar connections. A castable centering pin is used to connect and balance the denture during the final stage of insertion, even when millings or counter-attachments are not preferred. Male and female components come in 5 mm lengths but can be shortened down to 3.5 mm with no reported effect on functionality. This also helps dentists perform chairside clip replacement in the future.