Self-locking nut

Listed on the following equipment:
Technogym - 700 JOG NOW (DAK31L)
Technogym - 700i - D4683L
Technogym - DAK3AV - DAK31V - 0.2
Technogym - Excite Line - B3 New Bike DAC - 700 (DAC73L)
Technogym - Excite Line - B3 New Bike DAC - 700 WTV DIGITAL TV (DAC73D)
Technogym - Excite Line - B3 New Bike DAC - New Bike 700 (DAC73W)
Technogym - Excite Line - RE3 New Recline DAD - 700 (DAD73L)
Technogym - Excite Line - RE3 New Recline DAD - 700SP (DAD74L)
Technogym - Excite Line - RE3 New Recline DAD - WTV Digital TV (DAD73D)
Technogym - Excite New Recline (DAD5/7)
Technogym - Forma Line - Cross Forma D75
Technogym - New Bike DAC33W
Technogym - New Recline Excite Visio
Technogym - PG04 Adjustable Bench
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 (D241U)
Technogym - Run XT (D242U)
Technogym - Run XT (D243U)
Technogym - Run XT - D240U
Technogym - Step XT (D230U)
Technogym - Step XT (D231U)
Technogym - Top 700 - D4773L - 2.0 (S/N D4773L08000161-Below)
Technogym - Top 700 - D4773L - 2.0 (S/N D4773L08000162-D4773L08000362)
Technogym - TOP Upper Body Trainer - DA7 (DA773W)

* Images may not be identical to part.