The product specs are incorrect, or maybe they updated the bed frame from when it was originally made available. 

1. The slats are not wide wood as pictured, but rather narrow metal slats about 1/2" wide and 3/4" tall when assembled.

2. The slats are not 4" apart, but rather 6" apart.

3. The underside bed clearance is 13" *under* the bed.

4. The metal support rails on the side drop the underside clearance to 12.5" to get something like a storage container under the bed frame, and the **top** of the frame rails are 14" off the ground.

If you are expecting to store a 13" container under the bed, prepare to be disappointed. I had a difficult time getting a 12" container under the bed once the frame sank into the carpet.

The frame itself is solid once put together, so if those dimensions don't actually matter to you, it seems like a good frame.