This swivel cups will keep your springs happy during travel by allowing rotation and angular alignment. They work with our hollow screw jacks or you can run them on a stud on the rearend. Instead of a bolted together combo, our cup comes off by simply pushing the SLIC pin. This Patented SLIC Pin technology makes spring changes a breeze. This part number is our 5" spring 2-1/2" drop bearing cup 6" tall 1" screw jack.