Trans-mirrored R-bee (or down bun on bun) consists of two buns, reversed and facing each other with one row of dead cells between them so as to stabilize each other. It is one of the five possible ways to combine two buns into a still life. Its name comes from the fact that buns are also known as R-bees.
Trans-mirrored R-bee is the forty-fourth most common still life in Achim Flammenkamp's census, being less common than long snake but more common than JC. It is also the sixty-first most common object on Adam P. Goucher's Catagolue.