The FIAP Fish Grader 18 - 30 mm is buoyant and made of impregnated wood. The rust distances of FIAP fish sorter can be easily adjusted. From the handle of a mounted lever is operated with the thumb. The FIAP fish sorter to move diagonally like a diamond by pressing the lever at each notch up or down. Cycle through the sort rods a precise distance is maintained. All the assembled metal parts of FIAP fish sorter are rust (aluminium and brass).