Can confirm that the
Briggs & Riley Torq International Carry-On Wide-Body Spinner fits in a United Airlines sizer. The published/actual dimensions are 21.5x15.5x9, which is too wide for United's specs (got it for Air Canada where it is compliant). However, as you can see below it fits neatly in the United sizer - the wheels sit just under the lip of the sizer.
If this one fits then the slightly taller non-wide body version should also be fine.
