An interactive grid-based graphical trading system for use in securities trading provides a dynamic, visual display of trading data consisting of orders, quotes and indices, for any security and for any number of market participants. A porous metal container is implanted first and becomes fixed in place by bone growth. Further, the wire that couples the microcomputer chip and the memory chip to the testing conductive pad is coupled to a pad in the outer row among conductive pads in two rows to be coupled to the microcomputer chip. The water leaves the mop and is retained within a spin chamber of the bucket assembly. One or more diffusion apertures in the one or more sidewalls of the housing further provide a fluid communication between the interior region and a diffusion region external to the ion source chamber, wherein deposited ions are operable to diffuse out of the source chamber through the diffusion apertures. Also, a hanging file including a hanging member configured for hanging from a support structure, a file cover including a cover panel having a folded-over edge portion that is supported in a hanging configuration from the hanging member, and a support portion supported by and extending over the hanging member, and positioned between the folded-over edge portion and the hanging member.