It features an Arca-Swiss® compatible dovetail, while the slider is also equipped with an Arca-Swiss® type quick release clamp.
This Macro Focusing rail belongs to the higher-end focusing rails' class since the Camera to Subject distance can be adjusted in fine increments of 1.06 mm of travel per one rotation of the knobs.
On the other hand, fast positioning can be done by pressing a slider release lever. Besides its precise positioning for Macro photo stacking it may as well used as a nodal slide.
Thanks to Chris Hejna of Hejnar Photo, a sample is in my hands for some time now, so stay tuned for a detailed review soon.
Update Aug 27, 2013
Hejnar PHOTO MS-3_8 Linear Motion Macro Focusing Stage Review
The MS3_8 Macro Focusing Rail is available from Hejnar Photo online store.
New 50mm Linear Motion Micrometer Macro / Micro Rail from Hejnar PHOTO
New Hejnar PHOTO Linear Motion Micrometer Macro / Micro Rail