This is the drive on the bottom of the blender that drives the blades of the blender and attaches to the motor unit. Your old drive should unscrew off the blades for replacements. The new drives are white and will replace older Black drives and the newer Universal white drives Note: If you need a new one of these be careful to examine the high speed drive (next item on list) because usually if the drive coupling goes the results of the slippage will ruin the high speed drive as well