Lithium grease on my Haikelite o-rings

I am not an expert and I don’t recommend and suggest anything, just would like to show how my Haikelite MT03 o-rings looks like after 3.5 years in the lithium grease. In short, I don’t see any change in color, size, elasticity and softness.

This is the grease that I used:

It would be nice if somebody explain what material is this orange o-ring and is it compatible with a lithium grease.