Neewer 31.5"/80cm Carbon Fiber Camera Track Dolly Slider Rail System with 17.5lbs/8kg Load Capacity for Stabilizing Movie Film Video Making Photography DSLR Camera Nikon Canon Sony U-shaped ball bearings under the slider part to ensure both smooth motion and minimum abrasion on high-grade carbon fibre tubes Available for vertical, horizontal and 45 degrees shooting by using the threaded holes in the slider. Height of legs could be adjusted from 10.3cm to 13cm. Gear-shaped joint interface and locking knobs for better position locking for the legs. Easy to carry with an included carrying bag, excellent company for video making.