These 'shoes' are to replace the rubber feet on the Linksys WRT54G in order to wall mount the router with 4 screws.
You just have to plug in the brackets and glue them, or fix them on the case with screws. In this case, you need to drill 4 holes on the router's legs, at 6mm from the bottom
Other Linksys (Cisco) modems, routers seem to share the same enclosure such as:
WRT54GL, WRT54GS, WAG54G, ..
and these shoes might fit them too.
DXF, OpenSCAD, and FreeCAD sources are provided.
Feel free to modify this thing at your convenience. Good design is hard work, donations are welcome.