No Nick, no 'O' ring just the 3 glass syringes in styrofoam packaging.
Amazing they can do all that glass grinding to those tolerances for a buck each.
Mine were a bit more being made in Italy, but I didn’t buy them for fuel, I wanted to use them for boiling water.
My current plastic syringes hold up fine for fuel, I have had the kind that the black rubber “melts”. But none of my plastic ones hold up to boiling water... the whole thing deforms.