These are JIC x UNO male male nipples. UNO is widely used with USA made cylinder & valve ports. Please check thread chart below. JIC is also a USA thread, so if making new hoses, choose JIC hose ends.
To buy multiple quantities, click 'add to bag’, & then keep clicking 'add to bag' numerous times. Alternately, click 'add to bag’, & then at check-out there is an easy option to add whatever quantities you require.