fixed supports are not height-adjustable, but are useful in many types of installation.
From 14 to 35 mm

They are mainly used to ventilate the slab, protect the waterproofing membrane by distributing the load over an adequate surface, make the waterproofing system easy to inspect and repair, making it walk-on without overloading the existing slab. The circular shape adapts perfectly to laying surfaces, even irregular ones, and, for some, the body can be divided into two or four parts to be used along walls or right next to the corners. Some models are perfectly flat, such as Elastic and Mini Elastic, others have four spacer tabs in the upper part that allow you to create the joint.