This is designed to hold 3/8" air hose, or with adapters, to hold standard garden hose. It easily holds a long 5/8" extra heavy duty industrial garden hose. It comes with two 3/8" NPT male ended adapters that screw into the unit's 1/2" Female NPT fittings. You will need to buy two 3/8" NPT nipples, and two 3/8" female NPT to GHA (3/4" garden hose female fitting, the standard). My hose has the 3/4" standard fittings, and its inside diameter is 5/8", the most popular size. You will also need a standard garden hose female-female coupler, and plumber's teflon tape. The bottom of the frame has 6 slots designed for 1/2" or 5/8" lag screws. I mounted mine to 3/4" exterior treated plywood, and then mounted the plywood where I wanted it. You could also screw it to landscape timbers.

Other challenges:
This is not cheap. However, any hose reel less than about $300 will cost you a lot more, because you will have to replace it every couple of years. There is a version of this model which costs more and includes the hose adapters. If you store this inside over the winter, and re-pack the swivel with silicone grease yearly, it will last practically forever. Replacement seals are cheap and available. Note that it is heavy. I saved a lot by buying one from Amazon warehouse (where they keep the units whose packing boxes have deteriorated). I was short one of the 1/2-3/8 adapters, but I saved big. It turns out that these reels destroy the cheap boxes they are shipped in. Amazon repacks them in new boxes.

Assembly consists of screwing on the handle and adapters. The part where you will connect the hose to the reel between the two flanges is designed to put minimal stress on your hose. This is easy to reel, there is an adjustable brake so that you don't spin off too much hose, and there is a reel lock to keep it from moving. The steel in this unit is so good that it rings when you flick a flange. Made in USA!

Very happy with the new reels. I have 4 of them

Came on time like I needed it. The powder coating on this item is actually thick, I know because I scratched accidently. Packaging came beat up and holes everywhere i was lucky not to lose none of my part only reason I rate it 4 stars . You can actually fit more then 150ft of hose if reeled neatly so far no leaks product is working like it should planning to purchase another soon.

Came with a lot of missing parts... packaging was terrible. Use in a semi-professional setting, three times per week, it works great. Parts on it will rust...requires maintenance to prevent long term rust damage.

Great product