A robotic limb structure which is capable of achieving high speeds. A display assembly for displaying information may include a bracket adapted to be connected to shelving. The filter element includes a mesh including strands, each strand having a diameter. The disc includes a tabbing recess in its one face and into which a projected tab is received for insertion between the last and next sheets to be counted, at the moment of projection of the tab. A gesture and a corresponding control function are determined based at least in part on the first position and the second position. The sleeve includes a slot that allows for visualization and cutting of the ribbon.