The Rebco Flapper Bottom Adapter is an interchangeable bottom shoe sub designed to convert a standard ball-valve bottom bailer configuration to a flapper-valve bottom configuration, or vice versa, without replacing the entire bailer assembly. The flapper-valve design is preferred in wells where debris particle sizes are irregular or where coarser material, larger sand grains, small gravel, or scale fragments could jam or prevent a ball valve from seating cleanly and sealing the bailer after loading. The flapper closure mechanism accommodates a wider particle size range at the inlet and provides a more positive seal against backflow of debris when coarser material is present. The adapter connects via standard wireline thread and is field interchangeable with all Rebco SP, SD, and CH/CF bailer configurations.