Brass ring, with M13 opening in the middle. Also known as washer, cover ring or check ring. One side of the ring is sloping on the outside (see the photo for this).
interne diameter: M13 (of wel 1.3 cm)
|Dimensions (cm):||1.3 ,M13 (0.5 inch)|
|Thickness / depth (cm):||0.2 (0.08 inch)|
|Outer Diameter (cm):||2.4 (0.95 inch)|