These cartridges contain a small fraction of argon: 88.4% N2, 11.6% Ar by volume.
Food grade
Per-glass cost: 14.4 cents
Pressure: 2190 PSI
Nominal weight of N2: 3.2 g
Nominal weight of Ar: 1.0 g
Cylinder water capacity: 21 ml
Body diameter: 22.0 mm
Overall length: 86.0 mm
Cylinder neck threads: 3/8-24 UNF-1A