A small, implantable, non-bioabsorbable device intended to be attached to the top end of a spinal screw (not included) typically to secure/stabilize a rod and/or connector as part of an internal spinal fixation procedure. It is typically U-shaped with threads to receive a set screw and/or has a hole to allow the rod and/or connector to pass through; it may also facilitate a degree of motion. It is made of metal (e.g., surgical steel, titanium alloy) and/or synthetic polymer materials.