Structural component of the short non-contractile tail. The tail comprises six fibers made of gp17 trimers, 2 nm in diameter and 32 nm in length. May attach to host lipopolysaccharides (LPS) to mediate primary attachment to the host cell. Homotrimerizes. Interacts with tail components gp11 and gp12. Belongs to the T7likevirus tail fiber protein family.