There's so, So much more with this shock than just the double seals with oil chamber between them at the main seal head area, that is highlighted here. It's not just a conventional shock - eg: a damper shaft unit with an air chamber in place of a coil spring, with the air chamber sealing against the damper body. Note the lack of said, conventional shaft. Note the bladder allowing for oil displacement ( in combination with what appears to be a IFP - this IFP, could be the actual main 'spring' component of the shock - shades of old...