you are buying ONE bottle of Bad Black Moccasin fountain pen ink by Noodler's Ink
3 oz glass bottle is back!
Bulletproof refers to any Noodler's Ink that resists all the known tools of a forger, UV light, UV light wands, bleaches, alcohols, solvents, petrochemicals, oven cleaners, carpet cleaners, carpet stain lifters, and of course...they are also waterproof once permitted to dry upon cellulose paper.