They are plain black and made are food-grade. They have the tamper evident strip which breaks its seal when the bottle is opened.
Unused 6 Plastic Demijohn Cap & Grommet To Fit 5 Litre Plastic PET Bottles
2 x 5 Litre Food Grade Plastic PET Demijohns with Caps, Grommets & Airlocks
3Pcs/Lot Homebrew Carbonation Cap Plastic PET Bottle Carbonation Caps with Gaske
