I inherited this trundle bed frame about 20 years ago. I put it in my basement and never used it; my guess is it was used a handful of times by the people who gave it to me.
This is a nice heavy steel trundle bed. It springs up and collapses easily. The mattress support springs seem like new.
The overall size is approximately 72-1/8" x 38-1/2".
The floor-to-mattress base height is approximately 5-1/2" when collapsed and 15-1/4" when raised.