Step-down Housing Cap, 5mm to 4mm

Exactly what I needed.

Worked like a charm. I put V brakes on a old Trek frame that came with cantilever brakes and the cable needed to go through a thin welded on tube/cable guide past the seat post before going back to housing. This Step-down Housing Cap worked great to transition from bare cable in that little noodle back to housing.

Good fit for 1988 Trek

It's a good fit for the indentation where the internally routed rear derailleur cable exits the chain stay on my 1988 Trek 360..