You might be able to look it up online somewhere under "toro" if you have your model info. If possible that of course is going to give you their part numbers and more costly bearings. Most bearings are marked so you may be able to just read the bearing number and get at a bearing house or auto parts. If you can get the bearings removed intact even with no numbers a good bearing house can match them up by type and dimensions. Seems like I've had someone ask about this before. Seems 12 is part of the bearing number from a foggy memory. Maybe one of them is an R12. I don't know that just sounds right. I don't think they were the same top and bottom though. Anyway, good luck.