Original spare part from Sumec with reference number B223002001, named Fine hexagonal prevailing torque nuts (with non-metallic insert) for
lawn mower robot CLASSIC 500,
Robotic lawn mower EASYMOW 260, Robotic lawn mower MB 800, Robotic lawn mower CLASSIC 500B, Robotic lawn mower SA 650, Robotic lawn mower SA 650B