Product review (4 stars): If you are having trouble with the fit, this ...
If you are having trouble with the fit, this might help...

I purchased this item and ended up returning it because I thought it was incompatible with my refrigerator. The locking mechanism on this filter was different than the one I was replacing. So I bought the OEM version, and what do you know, it came with the same "wrong" locking mechanism on it.

Took some googling but I finally figured out what happened.

The manual for my refrigerator (RF266AEBP) calls for a #DA29-00003B. That has been discontinued, and the new replacement is #DA29-00003G. Somewhere in there the locking mechanism was also redesigned.

Apparently if you have a filter in place with the old locking design, it will release the filter before the locking collar is turned all the way. This blocks the new filter with the new design from going into the collar. So you have to put the old filter back in and turn it all the way to the left, past where the filter releases. Once you have done that, the new filter with the new locking design will just slip in, with no issues.

I found this info on Samsung's website and wanted to post it here in case people are having issues with getting the new style filter to fit.