Firestone Ride-Rite replacement air spring 6401. Rear 224C style double convoluted air bag with 1/4 NPT air inlet. 2,400 lbs. capacity.WARNING This product can expose you to chemicals including Lead, Nickel, Carbon Black, Chromium VI, and other Compounds which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.p65warnings.ca.gov.