X-form parachutes tend to provide a more stable descent as compared to the typical hexagon parachutes. They can also twist a little bit upon descent, so a swivel type attachment is recommended for the larger sizes. An X-form parachute also tends to pack more tightly than a comparable hexagon shaped parachute because there's less fabric overall.
This X-form parachute has both rectangles being 60cms (24") in length. The width of the rectangular sections is 1/3 of the length. So a 60cms X-form parachute has rectangular sections that are 20cms (8") in width.
These are constructed with the side panels sewn on separately which means that there isn't a double layer of fabric on top of the parachute. This allows them to be packed more tightly than other brands.