Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Strong pump, doesn't clog.

The Zoeller M57 pump is strong, clears water from my drainage system quickly. I replaced an Ace Hardware pump that, while strong, constantly clogged with Cypress needles. The M57 handles the needles and other small debris with ease. After a month of use, my only question is that the cast iron pump enclosure is showing signs of rust. That said, it would have to rust a lot to get through the heavy cast iron.