You are looking at a new MACK inner axle drive shaft. I am unsure of the original application. The one yoke is stamped 16N1820 which I believe to be a Meritor # for an 1820 series U-joint? The drive shaft measures 26” total, 23 3/8” center of bearing cap to center of bearing cap. The U-joint on the one end measures 5 3/16” across, the other end, 5 15/16” across. This is a new, never installed unit. It retailed for $1300.