The Jay Xtreme wheelchair cushion (sometimes mistakenly referenced as the "Jay Extreme" cushion) can generally be categorized as a gel cushion due to its pressure-distributing fluid-filled pouch component. Sunrise Medical—the manufacturer of this product—specifies this cushion as follows.
Sunrise Medical's "Tritex" cover comes standard with this Jay Xtreme wheelchair cushion. The outer cover's front pocket — available only on the Tritex cover — is approximately 4 inches tall by 5 inches wide (it tapers inwardly toward the bottom) and has a zippered closure.
A pair of adductor supports (i.e., the two light colored foam wedges shown in the picture on the left and right sides of the cushion's interior cover) are provided to help keep legs from moving beyond the left and right cushion edges. If desired, the adductor supports (i.e., the foam wedges) may be removed by sliding them out of their associated pockets atop the cushion's interior cover.
Note that the manufacturer—Sunrise Medical—recommends this cushion or the J3 cushion (also available here) as the replacement for the Jay Xtreme S cushion which was discontinued in Dec 2010.
Note that the manufacturer discontinued this cushion in September 2014. The Jay Xtreme cannot be ordered after this date.