High pressure power steering hose replacement

[Heavymental]

im about to replace my HP steering hose on my 95 LS.  i dont have any larger open wrenches and wanted to know this nut size before i DIY this.  i think its 21mm  but wanted to confirm.

see pic, red arrow:

[Lexus Owners Club]

I would be tempted to use an adjustable wrench to hold that union (also quite wide on the contact surface so less chance of slipping or chewing union)