3" diameter tube, steel end bells, and housing ends. Spring pad or suspension mount installation is additional. Installation - Service instructions can be found on Service Bulletin #0054. Due to the variety of options available, please collect your dimensions, know your suspension and how it will be mounted (4-link, leaf spring, ladder bar, etc.), then call 1-866-508-6394 or contact us to place your order. Installation - Service instructions can be found on Service Bulletin #0054.