WuFu is an open hardware and open source aid for blind people. Its name derives from the chinese expression “five bats” which denotes a symbol of luck and a long life. Like a bat, WuFu uses ultrasonic distance measurements. These are carried out by sensors on opaque glasses and are translated to vibrations of two motors. The motors are attached to the wrists of the wearer. The glasses hence can be used to gain a tactile feeling of the distances that make up the surrounding space. In addition, a compass sensor is used to provide feedback on the direction the wearer is heading in.