Don't know who makes them but AEM Factory make a similar product utilising a 45 degree fitting, as do Motocorse but they have a very different aesthetic.
They mount right into the master cylinders. I dont know who makes those. But I know that AEM makes reservoirs that mount like that. And motorcorsa makes a tear drop shape one that wraps around the top of your your forks. Although depending on the top clamp you have or clipons. The tear drop shape wont fit nicely. For example they wont work with Ducabike adjustable clipons ons, IMA Special parts clipons as well as the CNC racing and Ducabike top clamps. I have the tear drop shape ones on my 1299. But Motorcorsa also makes square one and they will work with any set up. The AEM reservoirs are made to fit OEM, RCS , RCS Corsa Corta and the other Brembo master cylinders Reservoirs
The Motorcorsa are made to fit all Brembo master cylinders. But they have specific ones for each type of master cylinder Reservoirs I have the square one on my Brembo 19RCS Corsa Corta on my Harley