Video description: Cracks A, B, C, and D are stacked on a 17.5' wall and being climbed by a sport climber. This crack setup climbs at a 5.10.
Crack Sections C and D. They work with Crack Sections A and B, meaning Section A can go with Sections B, C, D, and itself. All four sections were designed at the same time for maximum variability.
You can also purchase them individually as stand-alone rails.
Crack sections C and D have been designed together so that if you butt them as close as possible, you will get a 5.11+ seam on a vertical wall. This is assuming you don't try to cheat the holds on the top and face-climb the feature; however, good luck. We've thought that through, and even if you cheat the hold, you won't find any awesome sweet spots.
What is exciting about this crack system is that an amazing amount of variation arrives with a subtle 1/2" to 3/4" gap between the two holds. Offsetting the cracks, even just a few inches up or down delivers even more variety.
Section C is the jug side of this hold. For a detailed description, XXXL Granite Rail #3.
Section D is the sloper side of this hold. For a detailed description, XXXL Granite Rail #4.