Neewer 39cm SliderThis is a compact slider with proper ball bearing slides, 39cm carbon fibre rails, and a bubble level on the camera platform. Standard 1 4" thread for camera mounting, with a 3 8" adapter for head mounting (head is not included.) Honestly a pretty decent little device. (Note that you'll sometimes see this advertised as a 40cm slider, but the rods between the end supports measure 39. 5cm, and the end to end travel of the camera mounting point is about