I was a little skeptical on buying this machine " just because it seemed like a cheaper version of the rigid K50. But for the price I had to give it a try when renting one was the only other option. After it cane in 2 days , I was a believer lol. Gave it a try on a 4 inch cast iron line. And broke the clog up pretty quick in under an hour. Totally recommend for main drains up to 4 inch.