Inside a triangular frame of lightweight aluminum, power is transferred to the rear wheels via a silent clean Kevlar belt. Handlebars are mounted horizontally, so the rider can sit comfortably upright with an excellent view of the road. The genius of the triangular frame is that it can fold. In six seconds, you have a light, compact form that you can easily wheel before you, stow in a closet, load in your car or take on the train. Model 5.0 $799

Shop Review:

Light Weight, 22 lbs, great for rider between 5'6" to 6', good for on and off bus and subway, Very easy to wheel around when folded. Very low maintance with no chain to grease.

Not a good bike to share since it requires lots of effort to adjust the seat up and down.  Limit to one speed. Great bike if you like to spin very low impact on the joints.