Captive Segments - To prevent removal of bushing segments from the core shaft when the nuts and washers are removed, eliminating loss of individual segments.
Lanyard - To secure the removed fastener near installation hole to prevent loss and provide for easier installation.
Impedance Ring - Prevents loss of the fastener from the hole even if radial tightness is lost.
Dual locking features such as Cotter Pins, Lock wires, etc.