When you have two kids, you need a pair of everything so seach kid can get one when one inevitably asks if he/she can use it and the other wants one, too. (These poles are height-adjustable.)
But the dual-pole thing is pretty handy in challenging terrain. It was a bit overkill for this hike and they did quickly end up in the kids' hands. When they really came in handy was when I was hiking in Zion National Park (southwestern Utah) back in early 2003. The terrain is almost entirely sandstone, which can get slick when wet, and especially slick when icy. It the middle of a hike with some rapid elevation changes, a quick storm came through that unloaded a couple centimeters of snow pellets. My wife and I had an interesting time getting back down to the ground.
