A core adjustable dumbell sets up the same as a regular dumbbell, but it has an extra piece on top that lets it rest against the shoulder or side of your body, making it more stable.
The same holds true for a core adjustable weight set.
There are a few different types of core adjustable weights: the standard set with the shoulder and wrist rest, the wide and deep core adjustable, and the narrow and deep center adjustable.
This article discusses which type of core weight is best for your setup, as well as how to choose the right weights for different positions.
The standard set is best suited for a set of four, while the wide, deep, and narrow sets are great for a six-set set.
The wide and shallow set has four options: one set of eight, two sets of eight (plus a couple extra sets for extra weight), three sets of six, and four sets of four.
The narrow set has three options: two sets (plus extra sets) of eight and three sets (minus extra sets).
The narrow and core adjustable sets are best suited to beginners, as they have a little more range and can be used to improve your strength or power.
The wide and center adjustable are great options for heavier sets, but for heavier reps, it makes more sense to use the narrow set.