If your bottle screws into the max-flo normally ie clockwise then you will not need any converters...the air valve for the max flo has a reverse thread on it, try a bottle and then you will know. The converter would only be needed if you were puting CO2 into an air valved bottle before you connected it to the max-flo...please note that this only applys to Shockers not any other marker for the use of CO2, in-case someone else was reading this and was confused.