These are identical to burners sold by LampLight Farms. They take a 7/8"-wide replacement wick. A wick is included in each burner. Prices: $7.20 & $11.72
Burners operate efficiently ONLY when the level of the fuel is no more than 5 inches from the top of the burner, so many people add "ballast" to their lamp fonts or canning jars: pebbles, sand, aquarium gravel, seashells, marbles, nuts & bolts, etc. All of these items add colorful interest to the lamp(or jar), increase its stability, and reduce the amount of fuel needed to keep the fuel level high. None is soluble in kerosene, so has no effect on the cleanliness of the flame.
The lamp collars are sold separately on my COLLARS page: "#2 screw on collar"
BRIGHT finish, with canning JAR collar$7.20 each