Solid bed frame that converts from a twin to a king quickly.  Only issue seen is the slats for holding the mattresses are hollow tubing.  Even though they are spaced close to distribute the weight, I just can see my grandkids jumping on the bed and bending these tubes.  Also, the keyholes and keys on opposite frames match up, only won't slide into a locking position without raising the front legs of the main bed.  Guess I need to get & install leg leveling feet since they did not provide. If that doesn't work and the frames still won't lock, then all I got out of this is 2 twin beds.