I didn't install these valves myself -- my contractor did. He mentioned that they were on the more difficult side of the spectrum compared to other valves/faucets that he has installed. Additionally, I wish that I knew I had to purchase the value for the faucet I purchased (also on Wayfair). The reason for the 4 star rating is that there was some maneuvering that had to be done to make sure that one of the valves didn't leak.