Hate cleaning out those nasty smelling plaster traps? Not real confident about using acid treatments to dissolve the plaster? For nearly 10 years now our customers have been in love with the results provided by United 977. This Earth Smart® Certified product features United’s Earth Smart® Acid, providing you with a solution that is much safer than traditional treatments like Phosphoric and other acids. It is safer on drain lines, safer in use and safer for the environment.