The Luer taper is a standardized system of small-scale fluid fittings used for making leak-free connections between a male-taper fitting and its mating female part on medical and laboratory instruments, including hypodermic syringe tips and needles or stopcocks and needles.
It originated as a 6% taper fitting for glass bottle stoppers (so one side is 1.72 degrees from the centerline).
Key features of Luer taper connectors are defined in the ISO 80369-7 standards.
Slip tip (Luer-slip) fittings simply conform to Luer taper dimensions and are pressed together and held by friction (they have no threads).
Record connector, older standard for non-needle small diameter connections in Europe.