Pack of 2 - M12 x 1.75p Standard Nylon Locking Full nut in Stainless Steel.
These nuts use an Integral Nylon Ring to grip the thread when fitted. It is advised not to reuse these style nuts as once they have been fitted the nylon ring is deformed to mate with the screw thread. When removed the deformation remains in place significantly reducing the locking properties when re fitted.
They are also unsuitable for applications where heat is generated.