Unfortunately, the size XXL in the Senior jersey and the size 56 in the Pro jerseys are the largest sizes that CCM manufactures. Size equivalents are difficult with the different jerseys which is why we recommend taking a shirt that fits as you would like the referee jersey to fit, lay it flat on a table, and measure across the chest just under where the arms attach to the body of the shirt. Then, compare that to the measurements we provide on the sizing charts for both the CCM jerseys.
Please note that the largest size in the senior jersey (XXL) is slightly smaller than the size 54 in the pro jerseys (and you have a size 56 as well giving you two options that are larger than the largest senior jersey).