Self-locking nut

Listed on the following equipment:
Technogym - 700 JOG NOW - DAK31L
Technogym - 700i - D4683L
Technogym - Adjustable Bench - PG04
Technogym - DAK3AV - DAK31V - 0.2
Technogym - Excite Line - B3 New Bike DAC - (DAC73D)
Technogym - Excite Line - B3 New Bike DAC - (DAC73L)
Technogym - Excite Line - B3 New Bike DAC - (DAC73W)
Technogym - Excite Line RE3 New Recline DAD - DAD73D
Technogym - Excite Line RE3 New Recline DAD - DAD73L
Technogym - Excite Line RE3 New Recline DAD - DAD74L
Technogym - Excite New Recline (DAD5/7)
Technogym - Forma Line - Cross Forma D75
Technogym - New Bike - DAC33W
Technogym - New Recline Excite Visio
Technogym - RE1 New Recline 700 New Seat - DAD - (DAD33W)
Technogym - RE1 New Recline 700 Old Seat - DAD - (DAD33W)
Technogym - Recline 700
Technogym - Run 600 XT Pro
Technogym - Run XT - D240U
Technogym - Run XT - D241U
Technogym - Run XT - D242U
Technogym - Run XT - D243U
Technogym - Step XT - D230U
Technogym - Step XT - D231U
Technogym - Top 700 - D4773L - (SN D4773L08000161 - Below)
Technogym - Top 700 - D4773L - (SN D4773L08000162 - D4773L08000362)
Technogym - TOP Upper Body Trainer - DA7 - (DA773W)

* Images may not be identical to part.