25mm micrometer adjusting macro rail featuring a genuine Mitutoyo precision head, Delrin slider block, and 4-position quick release clamp. Hejnar Photo 10 Inch Lead Screw Micro Focusing Rail with 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.