I had just emailed BExpanded about attachments for my Bucket on B2650HSDC. Looks like all they have to fit my 60" bucket is Pirahna bar. I will be ordering one of those too.
They told me they were working on some other attachments for the B series, but outside of the tooth bar only supply things for the BX's since there are so many (and the buckets are much more uniform).
