
Please note in the comments at checkout what power steering pump and box or rack, and what booster you will be using. For example Type I or Type II GM pump, Stock Pump and Box for (year, make, model vehicle), or a Ford rack and pinion, etc.
The high pressure hose has the black cloth weave on the outside, it has a stainless braid weave in the middle, uses high pressure threaded hose ends, and is rated for aircraft use. The high pressure hose goes from your power steering pump to the Hydro-Boost and then from the Hydro-Boost to your steering unit.
There is about 1/10 of the pressure in the low pressure side of the power steering system. You only need a light duty rubber hose and hose clamps returning from your steering gear and from your Hydro-Boost back to the pump reservoir. You can use high pressure hose and fittings all around, but this is overkill by a factor of 10, and will be for looks - to have all the hose match.