I ordered this
https://www.amazon.com/gp/product/B07VL45LNB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
It looks like the lockring remover is about the right size. Note that it says, "Cassette / Rotor Lockring Removal tool fits Shimano, SRAM, SunRace, SunTour, Chris King and other...