Despite pushing the rubber protectors firmly on to the end of the pole and pressing down on a firm surface,I found that one of them had gone missing within a couple of miles on the first walk on a muddy trail. Just as well that I'd bought a few spares. They're now superglued on. I had the same problem with Leki rubber protectors on other makes of pole. Redesign called for so that this type of equipment is not so easily lost.
Protector fits snuggly over the pole tip and gives a wider area of friction on the ground than the metal tip itself so traction is improved. Seems to be hard wearing rubber but at the price I don't care if they wear out after a year or two.
I bought trekking pole tip protectors for my new black diamond poles and they are brilliant (both the new poles and definitely better with the rubber tips). We're in the mountains, over stony ground, and the rubber tips work better for grip and don't make that annoying click every time they hit rock.
Chalk bag with a difference