The Brain Coral Slab Crimps are tiny. To call them crimps is generous as on vertical walls, they are of the V6 expert difficulty. For most, they make excellent footholds you can smear on walls that are vertical to slightly overhanging.
Yet, they are pretty versatile for their size, as they can be used on volumes, around corners, as footholds, and as technical crimps on slab walls.
They're slightly slopey with varying differences in the set, making this an excellent set for vertical wall footholds. The intermediate climber can use these on vertical walls to look for more smeary/slopey feet. For the advanced climber, you can use these as feet in steep terrain.
You might be asking, how slopey are these as footholds? The holds stand off the wall almost 1 inch, so there is material to stand on. If there was such a grade rating for footholds, expect in the easy V3 range.