These housing ends are CNC machined from alloy billet steel. They are for street use only and have OEM style inner-axle seals for oil control. Two inches wide with a 3.150" diameter axle bearing bore. The bolt pattern is 3.557" center-to-center across the top, and 2" center-to-center vertically. The bolt holes are 3/8" diameter. Kit contains a pair of housing ends.