Do knee sleeves stretch?
The sleeves will stretch after some use. They should feel snug and even uncomfortable if you've never worn sleeves before. However, they should not cut off the circulation or interfere with your range of motion. If the sleeves are so tight that they do either of these two things, I would recommend the next size up. Just let us know and we will do everything we can to accommodate.
If you are still unsure, feel free to use them for a couple weeks and then let us know what you think.