My house is over 60 years old, and the pipes under the sink is clogged up with all the grease and sediments which prevented the water from flowing. So I called up Wah Hing Plumbing Ltd to set up an appointment to fix up the problem. The plumber is on-time for the appointment, he inspected the old pipes and quoted me a price of $300 to replace the old plastic tube and take out the materials that clog the metal pipes with one of his machines. He didn't come prepared with a bucket or pail, so some water leaked onto my floor and the shelf space underneath the sink. He did just an OK job afterward to clean up the mess. Overall, the water flows much better after he removed the clogs, and the sink is working fine so I am satisfied with his service. Also, he offered a warranty of 30 days, in case anything goes wrong, he will come back to fix it for free.