This OEM Hendrickson S-20001 Shock Absorber is commonly found on Hendrickson HT190T Top Mount & HT190U Under Mount suspensions. Hendrickson trailer shock absorbers feature solid inner metal bushings, specific stroke lengths, special bore diameters, and unique seal designs. They are specially designed to offer superior fit and functionality, improve damping life, optimize system performance, and reduce overall maintenance of your Hendrickson suspension system. Hendrickson genuine shock absorbers are made to withstand Hendrickson’s high torque level requirements on the mounting bolt.