Complete trephine set. Set contains: - 8 x Short Trephine Drills ( 1 x 3.0 mm, 1 x 4.0 mm, 1 x 5.0 mm, 1 x 6.0 mm, 1 x 7.0 mm, 1 x 8.0 mm, 1 x 9.0 mm, 1 x 10.0 mm ) - 4 x Long Trephine Drills ( 1 x 3.0 mm, 1 x 4.0 mm, 1 x 5.0 mm, 1 x 6.0 mm ). - 1 x Depth probe.