Thank-you.You were very helpful in directing me to the right part. My trainer is old with no numbers on it. The actual part is probably not available any more. The part I ordered was too small in diameter, but that is what all the new ones are probably like. I was able to make it work with a couple of 3/4" pex rings that fit perfectly around the shaft of the part and the I side tube of the trainer. Thought I'd let you know in case someone else runs in to that issue. Thanks again to you I'm riding again this winter.