I have ordered Nissin components for several bikes over the years. Typically they only have three varriant colors. I don't know if it was a production thing, or they gave me a OE bike spec'd one off of a currnet production run, but one time when I ordered Black they sent me one similar to the color of the one on the right.
Anyone know why the inlet is different?
They both look to be Radial Types, just the one having the reservoir coming out the side is a newer version.
(One on Right or lighter color. Which is all they manufacture now in a Radial.)
"The vertically angled body lets the lever flow fluid directly through the master cylinder giving it a sharper response."
At least that is what Nissin says in it's brochure... Follow the link to the two different styles.
For refference.
https://www.shindypro.com/brake_mckits.html