Having climbed for many years I was used to using a "heavier" set of extendable poles that always seemed to collapse at the wrong time. I heard about the BD Distance poles and talked to other ultrarunners who had used them. I bought a pair specifically to use at Hardrock in 2011. Showed up three weeks early to acclimate and do course marking. Used the poles every day. 2011 brought a lot of snow to the course and poles were very helpful. The first thing you notice about the poles is the complete absence of weight. You almost forget they are in your hands. Although the poles are extendable, there are no screwing mechanisms to fail. The way the poles fold up and out is almost foolproof. Once extended, the internal "green ooze" provides a bomber lock. For their light weight, the poles are very durable(although the one mishap we saw during the course marking resulted in a snapped pole for a friend when he postholed in deep snow, lost his balance, and levered the pole in the snow, snapping it off; but BD replaced it immediatley). Despite that, these are great poles for running in the mountains. Buy 'em.