Where to mount my Eley hose reel?

What are the 'actual' wood post dimensions that this will mount to?, Lumber dimensions are a bit misleading. When the board is first rough cut from

Wood Post Mount Kit

Free-Standing Garden Hose Reel

ELEY Hose Reel Wall Mount - Garden Hose Reel Wall Mount and Garden Hose Holder, Expertly Designed Water Hose Reel and Hose Wall Mount

Eley Hose Reel and other Eley things #Eley

Where to mount my Eley hose reel?

Highest-rated. Durable aluminum construction. Easy mobility with flat-free tires. No-tip stability. Drinking water safe. 10-YEAR Warranty. Midwest

2-Wheel Garden Hose Reel Cart

Wall Mount Garden Hose Reel – Eley Hose Reels

Highest-rated. Durable, aluminum construction. Low-profile, wide no-tip design. Drinking water safe. 10-YEAR No-Leak, No-Break warranty. Midwest

Free-Standing Garden Hose Reel

4 Wheel Garden Hose Reel Cart – Eley Hose Reels

Eley Hose Reel Installation // How To For A Post vs Wall Installation