Tubular Box Spanner Set made from high-quality durable carbon steel, and coated with zinc to help prevent corrosion. The Spanners have hexagonal sockets and two holes for mounting the bars. Comes with a foldable nylon roll-up case. Technical Data: Material: Carbon Steel Sizes: 6x7mm, 8x9mm, 10x11mm, 12x13mm, 14x15mm, 16x17mm, 18x19mm, 20x22mm, Includes 2 handy tommy bars. Number of Pieces: 10