M8 ‘LEFT HAND THREAD’ TITANIUM plain half nut
DIN 934 spec
M8 x 1.25mm LEFT HAND THREAD.
It’s a half nut which is roughly half the height of a normal plain nut.
Left hand thread is the opposite direction of thread and is used things like gear change pushrods
Here is a lightweight titanium M8 nut. It’s totally corrosion proof and super strong
Weight = 2.9gm