Double Jacket Fire Hose 1 3/4" USA Made fire hose is manufactured to NFPA 1961 specs and is suitable for water pressures up to 400 psi. 1.75" fire hose offers more flow than a 1.5" diameter hose but still features the same 1.5" fittings so can connect to either 1.5" fire hose or 1.75" fire hose as long as the thread type is 1.5" NH aka NST. We do not offer 1 3/4" fire hose with NPSH threaded couplings. The double jacket hose category is our most durable hose and fire hose with color treatment offers the absolute maximum durability. We only offer 1.75" fire hose with NH aka NST threaded couplings.