Instruction: Given a question and its related document, determine if the question is answerable by analyzing the information in the document. Output yes if the document addresses the question, or no otherwise.

Input:
Question: Does this include 2 pulleys or just one?
Document: Nothing elaborate about these pulleys, but they work fine and get the job done.I have limited experience with other pulleys, my comments are limited.
What can I say, it works well on my Ultegra. My old one cracked in half, so I bought this one, and it works fine.
Direct factory replacements. Solved a problem for me. The bike seemed to be heavy and i was sluggish, a good cleaning revealed a frozen pulley wheel! I just got the bike out of the shop 2 weeks before. The set I had before was less than 2 years/3000 miles old.
I bought this to replace a pulley set that I thought was fouled since the top pulley seem to spin less freely than the bottom one. The replacement set has the same issue and I have seen some reviews where the riders simply replaced the impeded top pulley with a new bottom one to reduce resistance. So the product is fine and as engineered - I am just wondering why it was engineered this way.
Well priced and quickly shipped. I'm pleased. There's not much else to say in my required word count for the review,
Used these to upgrade a Tiagra 9spd rear derailleur - worked perfectly! derailleur shifts clean and quiet now! well worth the effort
This product as you would expect works without any problems in installing it or in the operation of the bike
The top ceramic pulley did not spin as well as the bottom sealed bearing pulley. So I replaced my old top pulley with the new bottom pulley with good results. RD shifts better than before.
The pulley set transformed my ride, the quality is excellent. It very easy to install with the right tools. It was delivered on time as promised.
Shimano - good quality as expected. Everything wears eventually. I may have been able to keep the old ones going for a while, but at this price I had no more excuses.
Answer: yes