The mecablitz 15 MS-1 is a ring flash unit that seems to have nobody to love it. I started with the maker's URL at /grog/photography/mecablitz-15-MS-1.php, but that failed, so I tried another at https://www.metz-mecatech.de/en/lighting/flash-units/specialist-flash-units/mecablitz-15-ms-1-digital-kit/product-information.html, but that also went away, so I found an alternative at http://www.m43gear.com/2014/10/for-amazing-macro-shots-try-metz.html, but that domain went away. The best I can do is a web search, but that's not very helpful either.

The best I can find is here, in Spanish, which at least has a good image:

The flash can be operated directly with a sync cable, but only in fully manual mode. It is intended to function as a slave flash, requiring the toy on-camera flash to provide the control, as shown in the photo. The funny black thing on top of the camera is a clip supplied to prevent direct light from the toy flash.

The unit understands most flash TTL protocols, and it has a guide number of 15 at 100/21° ISO. It has flash direction settings for different distances, and I've found it very difficult to adjust the thing.

Since Metz went out of business, the firmware download page has gone away. This page might help.