They are the same shell if that's what you mean. Different padding. The XL and XXL is the larger shell
The G3 is available in six different helmet sizes through padding installed in two shell sizes creating the most comfortable fitting helmet on the market. Using a tape measure please determine the circumference of head to the nearest 1/8 of an inch. Do this by placing the tape measure around the widest part of your head which will be above the eye brows and ears. Available sizes include: xsmall (51-52 cm or 20-20.5 in), small (52-53 cm or 20.5-20.75 in), medium (53-55 cm or 20.75-21.5 in), large (55-57 cm or 21.5-22.25 in), xlarge (57-59 cm or 22.25-23 in) and xxlarge (59-61 cm or 23-24 in).