Take on the world together. The mountain buggy duo is a side-by-side double stroller with the maneuverability of a single stroller. The Mountain Buggy Urban Duo stroller is the latest version of the popular Mountain Buggy Urban Double. The Duo is built on a durable yet lightweight aluminum frame, and is perfect for parents with twins or two children who are close in age. The Mountain Buggy Duo now features independent canopies over each seat, an included bumper bar and bottle holder, and an updated 5-point harness that provides extra padding and safety features.