Hi Carfin, the "KF" marking is for Kältefest (cold weatherproof) and that Invarol grease used inside the binos.
"O": a light blue circle indicates Grease no. 1416 which would work down to -40 deg c.
A blue cross indicates Grease no. 1442, again supposedly functional to -40-deg C
The triangle again refers to the type of grease used: in this case the later improved type of grease.
Hope this helps?
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Thank you Ade, what a précise information, yes it does help very much.
Best regards from Alsace, France.