Description: Standard 1/4" Screw Top & 3/8" Hole Bottom: compatible with Canon, Nikon, Sony , Arca Swiss more camera, tripod, monopod, monitor and other macro focus photographic accessories. Help to focus on the subject in short distance. Close-up Focus: fine-tuning control within 115mm adjustment range. Adjustable Sliding Speed: to slide slowly, or move quickly. High Quality: made from CNC aluminum alloy, anodized surface, light weight, durable and not easy to wear. The rail is driven by a worm gear (knob control), and an index scale (in millimeters) is printed on both sides. Specification: Material: Aluminum Alloy Size: 21.2x4.8x3 cm/8.3x1.9x1.2 inch Package Includes: 1x Tripod Quick Release Plate
