Bolt Pattern (top): 10.5� W x Slotted Slides Bolt Pattern (bottom): 10.25� W x 5.25�, 6.5�, 8.63�, 9.63�, 10.75�, 12�,12.75� D Fits Concentric Seat Models: 11000, 11500, 12000, 13500, 14000, 32000, 34000, 35500, 44000, 44100, 45000, 46000, 50800