I purchased a DA12 polisher and on first use it started behaving erratically after about 1hour then stopped working completely. I returned it but it was shipped back to me after Autobrite used it and didn’t experience a problem. Unsurprisingly, when I next went to use it it failed after polishing one panel. I shook it and it started working again but obviously returned it once again (at my expense). Autobrite used it as before and said that they didn’t experience any issues. They are refusing to refund or replace. I don’t believe that they have any technicians capable of testing or repairing such items. Do not trust