Hi redbird,
If you scroll down to near the bottom of the page (to the right of the picture of the picture of the foundation that says “Fully Upholstered 9” High") you will see a box that lists the ILD range of their 4 firmness choices.
I would be very cautious about using just the ILD numbers for a single layer as a way to compare the firmness or feel of two mattresses that have different designs because the type of latex, the thickness of the layers, the firmness of each layer, and all the other layers and components (including the cover) will all have a significant effect on how the mattress feels and how it compares to another mattress or “matches” a particular person in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences). I would also keep in mind that the Flobeds mattresses use a 2" layer of convoluted latex in the top layer that is 28 ILD but would “feel” closer to the mid teens in terms of firmness because of the convoluting (which they will also change out for a solid layer with a different firmness level on request).
Using ILD information by itself without taking into account all the other parts of a mattress design and all the other layers that can also affect the feel and firmness of the mattress can be somewhat misleading because only individual layers have a rated ILD … not the mattress itself.
There is also more about the different ways to choose the most suitable mattress (either locally or online) that can help you assess and minimize the risks involved with each of them in post #2 here.
Phoenix