The piston seal type Aston Seals KGD is composed of a sealing rubber element with low permanent deformation which assures good sealing performance. Three compact and small seal edges ensure perfect fluid control and concentrate load against the dynamic surface. The cavities between the external seal edges keep small quantities of fluid reducing friction and wear. The special geometry of static side guaranties a wide contact area and prevents distortion inside the groove during installation - Two anti-extrusion rings with stabilizers to avoid the rotation of the rubber element. A special geometry of grooves assures that pressure loads the energizing seal element without any risk of extrusion of it. - Two angular wear rings which guide the piston in the cylinder tube and support radial loads. Special grooves ensure that pressure loads the energizing seal element in all work conditions.