Par for the course as Convert-a-ball is a loser of a company with ZERO R & D and no improvements over the years.  If I could give it a zero, I would.  The lid only has tiny catches on the long sides and it is cast out of limp plastic and the bulging sides don't grip the base so the lid pops off.  It should hinge and be attached permanently.  It is third one I have owned over the years and the only option.  They know it and abuse that fact in their lack of improvement.  If a company could just come along and do it right these guys would be history.  Lack of competition breeds complacency.