IBM - 44W4899 - Power Backplane 3.5-inch 44W4899 - IBM - Power Backplane 3.5-inch for x3550 $54.24 $44.10
IBM - 39Y6972 - Power Backplane Board x3550 39Y6972 - IBM - Power Backplane Board for System x3550 $30.73 $24.99