I purchased this trundle to fit under my matching twin bunkbeds. I was a bit sad to see that it doesn't quite fit under the frame. If you took out the middle support in the back, it might fit better. I didn't try that since I believe the support is necessary. It's not quite flush, but I don't believe it's a tripping hazard. Also, I strongly suggest a 5-inch twin mattress. Once I assembled the trundle, I realized the recommended mattress size will not work.
Not Great, Will Work
I purchased this trundle to fit under my matching twin bunkbeds. I was a bit sad to see that it doesn't quite fit under the frame. If you took out the middle support in the back, it might fit better. I didn't try that since I believe the support is necessary. It's not quite flush, but I don't believe it's a tripping hazard. Also, I strongly suggest a 5-inch twin mattress. Once I assembled the trundle, I realized the recommended mattress size will not work.