I like the Flexzilla brand and have both air and garden hoses. When the 3/8" red rubber hoses started cracking on the Harbor Freight reels I replaced them with 1/2" Flexzillas. The rubber hoses have thicker walls so I the 50-foot Flexzilla replacement fits just fine.
I put a triple plug on a short whip so I can attach three air tools at the same time and the whip can be moved to another hose when I'm working outside.
Just like the 50-foot Harbor Freight reel, the 3/8" red hose on the Costco reel was cracking and the 25-foot 1/2" Flexzilla hose fits. The green shower head on the pipe is my way of blowing the dust off me at the end of the day before I enter her ladyship's domain (dumps the air out of the liines as well)..