washing machine outlet box

Hi all,
I'm looking to install a washing machine outlet box. I have 2 questions:
1. What do you guys recommend (I like the Sioux Chief Ox Box)?
2. What is the installed height off the floor?

This will be on a bare wall (no counter top) right behind the washing machine.
Thanks all.
Billw

42" above finished floor.

I like the OX-Box!