The bottom rail includes compatible dovetail that works with clamps while the slider is equipped with quick release clamp. The clamp can be oriented in 4 positions. Camera to subject distance can be adjusted in fine increments. Lead screw delivers 1.06 mm of travel per full revolution. Fast positioning can be done by pressing slider release button and slide the slider to required position. Maximum travel distance 5.5 inch. Macro rail use Self Aligning Linear Sleeve Bearings. Virtually maintenance free, they have a nonabrasive, chemical-resistant PTFE liner that doesn't require added lubrication. Shell is aluminum with a 0.002" thick ceramic coating for added corrosion resistance. Temperature range is â€“400Â° to +375Â° F. Rail will work in 90 degree orientation (perpendicular to the ground) with load up to 10 lbs. When rail is in horizontal orientation (parallel to the ground) it can hold up to 15 lbs.