Shimano PRO Saddle / Tracer Mount

This adapter will mount a Tracer rear light tucked under a Shimano PRO saddle with the integrated saddle mount, requires two 4 mm (M4) x 8 mm button or socket head cap screws to mount under the saddle. 

Why are there two choices for black?
All 3D prints are made from the same raw white Nylon materials. Black Natural Versatile Plastic is a print that comes straight out of the printer, is cleaned and then placed in a black dye bath. Black Natural Versatile Plastic is not polished or surface finished in any other manner. The result is a grainy/fuzzy surface texture. Professional plastic starts with similar raw material and a liquid binder (gray) resulting in more even and saturated color when dyed. Professional Plastic has a smooth semi-gloss finish. Professional Plastic produces a stronger print.