Okay, I've ID'ed the black hose by accident. It's an extension hose for the Kenmore direct drive/beltless upright. It may fit other Kenmores that I don't know about. However, it's an electric hose and that's part of what fooled me. There aren't many uprights that take an electric hose. Some of the Kenmores, including some of the earlier direct drive/beltless models, came with an electric Power-Mate Jr. for doing stairs, etc., and that's why the electric hose.