[1/4"-20 Male] I used this rail in a stop motion animation where i had to move the camera vertically each frame.this rail had no problem holding the position of the camera for each frame even with the camera mounted via and l bracket and a 135mm lens on it. No slipping at all.

[3.9" / 9.9 cm] Exactly what I needed to complete my macro setup. Paired with Novoflex Castel-L rack to give x and y focusing ability.

[0.905 lb] Already purchased and am using a Novoflex CASTEl L, but the one direction (in/out), just wasn't sufficient for good macro work. The quality of the Novoflex rails is excellent and B&H Photo processed & shipped my order quickly and was well packed/protected. Just added a new 3-way Manfrotto tripod head and am ready to conquer the world of macro photography.

[0.905 lb] Solid build and very smooth movement in very fine increments, if necessary.My only gripe would be, that the knob that drives the stage would benefit from being a bit bigger (there's a fine focus attachment for it, but that is an additional $) and/or having a degree scale or click stops, as it would make focus stacking a lot easier. I did a quick focus stack (in CombineZP and Picolay), which came out fine, but having a way to move the stage in consistent increments would be a big plus. 5 stars nonetheless.

[3.9" / 9.9 cm] I did a lot of research and picked the Castel Q. It works perfectly with RRS L plates.
It is well built and the right size. I’m using it with a Hasselblad X1D, Leica M, SL, and Q.

Smooth operation.

[0.905 lb] all about Arca Swiss compatibility I was happy to see the precise fit for the plate and the base. This is a work of art.

[1/4"-20 Male] Very solid build. Quality product which just glides through the micro adjustments on the focusing rack. Holds its position on the rack without the brake knob engaged up to about 70 degree incline with my macro kit of Nikon D7500 Kirk L bracket and Tamron 90mm macro lens ( combined weight approx. 3.6 lbs. ) It can very slowly creep between 70 and 90 degree incline but I use the brake knob when focus is attained. Great for focus stacking but I also use it in the field for micro adjustments to focus more precisely. Bonus is it also works well as nodal point rack for panoramas. Very pleased with the purchase and advice and service from B&H. Well worth the cost.

[0.905 lb] What is there to say? It's just fantastic. I own three other brand focusing rails, and this one, by far, outshines them all. The focus knob located on the side is very accessible and turns very easily and accurately. The smaller knob on the other tightens the position. The ARCA type adjustment on the rear easily secures the camera to the rack. I have found it is easier to loosen and tighten when it is at the rear of the rack. Buy it, you'll like it.

[3.9" / 9.9 cm] If you want to mount a camera for macro use, this is the best available. If you want to mount a lens, get the Kirk macro rail (the quick release can be rotated). This rail won't fit the RRS lever quick release (I had to swap mine out), so be warned against RRS clamps. Once you've worked with this rail, others seem antiquated and crude. This product is perfectly thought out and brilliantly executed.

[3.9" / 9.9 cm] It arrived in perfect condition.