Precision Macro Focusing Rails for Macro Photography

4-way macro focusing rails with two rails (one goes left-right, the other goes forward-back) to assist in macro photography. While it can be used with just one of these, I find having two assembled (as shown in the picture) makes it easier when focusing closely. Precise movements are especially useful for focus-stacking.

The only thing I don't like about these is the red-colored knobs. Since these are used at such close proximity to the subject, these could contribute to unwanted color cast. Would have been nice if they were left black, like the rest of the parts.

(image shot with Sony 55-210mm lens on Sony a6000 camera)