Features: Super Mag Macro Focusing Rail Slider corrosion-resistant magnesium alloy macro-rails consist of X and Y movable tables for precisely adjusting focus threaded holes for mounting the top table to a tripod The Velbon Super Mag Macro Focusing Rail Slider, essential for precision macro photography, is made of a lightweight, corrosion-resistant magnesium alloy. Even with a steady hand, macro photography can be tricky and temperamental. The fine tuning of the Super Mag Slider helps you find the right depth of field to take precise close-up photos. The smooth action macro-rails consist of X and Y movable tables for precisely adjusting focus. The X axis moves right and left, the Y axis moves towards and away from the operator on threaded rods. By using the included allen wrench you can separate the top and bottom tables for additional modification. Underneath the top table (Y), there are both 1/4 and 3/8-inch threaded holes for mounting the top table to a tripod. The adjustment knobs are smooth and fluid, and have just the right amount of resistance.