CTA products model 7650 is a low air pressure ATF drain tool for Mercedes and BMW. This is the first time using on a Mercedes 2015 C300 4Matic that has a 722.961 transmission. I paid for and own this and am not sponsored by CTA products.
This product is discussed at more length at the mbworld forums:
mbworld.org/forums/c-class-w205/768205-2015-c300-4matic-atf-722-961-cta-7650-atf-low-pressure-drain-tool.html