Here is a very lightly used Kent-Moore fuel pump module lock ring tool. IIRC it fits the larger GM SUV’s. I’m retired and no longer need it. It has my initials lightly etched on it.

https://www.toolsource.com/fuel-line-filter-wrenches-c-1321_182_186/fuel-sending-unit-wrench-p-112117.html. This is it

More info on what this tool does