UNTESTED - stay tuned for final statement about quality etc.
O-Ring Specifications (unpolished):
Inner diameter of 3.5mm
Outer diameter of 8mm
Thickness of 2.25mm
Check out all variations:
3.5cm
3mm hole 3.5cm
3.5mm hole 3.5cm
3.5mm O-Ring 3cm
3.5mm hole 3cm
2.5mm O-Ring 3cm
3.5mm O-Ring