Item InformationThis 2 ways vernier regulation macro focusing rail slider can works for almost all digital/film SLR cameras. It is suitable for most Canon Nikon Pentac Minolta Macro/EOS bellows macro shot extension tubes or macro lenses such as the Canon FD and FL.One 15cm rails can support movement of 2 directions—forward, back.Positive locking knobs assure rock-steady focus. Feature:1.This vernier regulation focusing rail slider is designed for all digital and film SLR cameras.2.It is suitible for most Nikon, Minolta and Pentax macro andEOS bellows, macro shot extension tubes, or macro lenses such as the Canon FD and FL.3.Smooth rack and pinion movement provides extremely fine focusing adjustments.4.Smooth rack and pinion movement provides extremely fine focusing adjustments.5.The geared drive system can geatly enhance accuracy and speed of adjustment of the slider.6.The screw size is international standare : 1/4". And it will fit most tripods and copy stands. 7.Positive locking knobs assure rock-steady focus.8.Focusing rails are essential accessories for macro photography, which requires precise distance modifications and a steady hand, as well as other situations where accurate camera positioning is crucial.9.Used for macro photography, or film negatives taken.Specification:Material: made of Metal (Aluminum alloy)Weight:220gLength:160mmRange adjustable: 100mmSuitable for:All digital and film SLR cameras:most for Nikon, Minolta and Pentax macro andEOS bellows, macro shot extension tubes, or macro lenses such as the for Canon FD and FL