BreezeBlockers produce a variety of handlebar-mounted wind shields for your hands, similar to those you see on some motorcycles. We reviewed the Aeroblade a while ago. The D.Flektr is one of three versions for mountain bikes and flat-bar commuter bikes.
Fitting is straightforward, at least in theory. An expander bolt with a peg on the end-cap fixes each D.Flektr to the end of the bar, while a rubber O-ring secures the other end in between the brake lever and gear shifter.