Downrods for ceiling fans are generally not universal since they vary in length and diameter depending on different manufacturers and models of fans. It is important to choose a downrod that matches or is compatible with your specific fan model in order for it to be safely installed and properly function. When purchasing a downrod, make sure you select one that is recommended by your fan's manufacturer or choose a universal downrod designed specifically for your particular brand of fan if available. Always refer to the manufacturer's instructions or consult an expert for guidance when selecting and installing a downrod for your ceiling fan.