I used these trolleys to install swings/hammocks/ropes on an i-beam in our basement. They have worked perfectly and were easily to install. The dream was to have swings, ropes, etc on the beam and be able to roll as an indoor "zip-line". It works, but geez is it loud. The metal on metal rolling of the trolley on our metal i-beam sounds (and feels) like we're at an amusement park waiting in line for the roller coaster. I attempted to cover the wheels with rubber as well as line the i-beam with felt and rubber, but it was just too loud when rolling to keep the zip-line function. I'm still glad I purchased the trolley instead of a fixed bracket as it is easy to move them around the room as needed, but really wish I could leave it "unlocked" and let the kids (and ME!!) swing around the room on our indoor zipline. Overall, these are built really well, are heavy duty, and should work for most "normal" applications well.