What is the most frustrating product that you own?

My weed whacker bit the dust this week. Never did work properly. The bumper on the wheel spool finally wore down past the nub and launched itself through a rip in the space-time continuum in an impressive trebuchet sort of way. Never to be seen again. And I looked.
Searching for a new one is proving difficult as everything is built half-arsed now and feedback is filled with honest and repelling replies. So duct tape it is until the one I decided on is back in stock local. Should be a week or so.
What is the most frustrating product that you own?
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