This is one of those perfect applications for a 3D printer at home. A fence build a year ago by a sub-contractor was inspected and some pole caps where missing. Having no idea of the make and model of the poles we didn't have a clue of where to buy such caps. A few minutes in a CAD program and two hours of automated 3D printing solved the problem and now the poles are protected from rain. How will retail stores and spare part supplies look like in the future? :)