New units. Various sizes. Each purchase is for one.
NOTE: all nozzles in this listing without an H designation are S-S (semi-solid spray cone)
I found some more info on the net and the cross reference chart--
On oil nozzles, the first number is gallons of oil per hour at 100psi.
The second number is the apex angle (30° to 90° arc) of the oil spray cone.
The letters designate the fill of the spray cone: A or H = hollow, B or ES = solid, SS = semi-solid, W = multipurpose.
If you have specific type questions I will do my best to answer however this item is not something I am familiar with so I can't offer any technical advice.