Stand mixers with a date code (located underneath the power head) of 9601 to 9752 must use beaters with a compression ring on them. The compression ring can be found just under the ears on the beater stem and is a thin wire that goes completely around the beater stem. The P9-311 and P10-311 beaters are not interchangeable. Please inspect your current beaters and view the image next to the P9-311 to determine which part you need. The P10-311 beaters are no longer available.