10-Inch Hejnar Photo Arca-Swiss compatible lead screw micro focusing rail with rapid-positioning release button and modular 4-position clamp. 50mm high-precision macro focusing rail with 100 TPI adjusting screw drive and indexable 4-position quick release clamp. 25mm micrometer adjusting macro rail featuring an ultra-precision Mitutoyo head with 0.001mm graduation increments and a 4-position quick release clamp.