Very sturdy.I used the tip from a fellow buyer and purchased car mats to keep the mattress from sliding on the frame, and it worked. Prior to that, the mattress slid very easily off the frame.

Very pleased with our new king size base. Being a larger framed person this bed base is supporting the weight really well. So far we love it and recommend this base. Very easily assembled as well.

I bought the twin rails for my grandkids guest bedroom. They worked really well. Plenty of room to store things under the bed. Glad I bought this product.

I bought this for my son and he is heavy. It adds extra support and he said it is very comfortable.

Very stable and solid construction. 14” height is great.

We like this as we are short people and a box springs just makes the bed too high for us.

Very excellent product very Sturdy and firm will definitely recommend

Squeaks and moves when we get in the bed

Purchased this because the "Bed Frame Expert" here on Sam's site stated that the openings were 3". Most bed in a box manufacturers are now requiring that you have it on something where the gaps are no larger than 3" to 4", otherwise it voids their 100 day return policy and any warranties. This is 4.75 in one direction, and just over 9" in the other. With no one on it, our king size mattress is protruding down through the openings which means it's not getting adequate support. I'd never have purchased had an accurate answer been posted, and now i've got to box it back up and figure out how to ship it back (it's too heavy to lug into a car or truck).