Looking for free or cheap matresses (N Fruit Ave) - N.A. - (Fresno, CA)

I have a metal bunk bed for my kids but no matresses. The top and bottom are the same size. They're about 39" wide which is a twin size I think. Doesn't need to be brand new but I am planning on letting my kids sleep there so no extreme cases please. Text with any opportunities or leads thank you. I'm a night owl so text anytime don't worry about the hour 559-473-XXXX. Location: N Fruit Ave