CustomFit offers two different constructions for some sweaters.
The set-in sleeve construction is available as an option on every design, and is CustomFit’s original default construction. Most photographs on the site are of set-in sleeve sweaters.
The drop shoulder construction is available on some designs, and will produce a sweater with the general design options as shown, but with modified drop-shoulder armholes instead. This will produce a looser garment than a set-in-sleeve garment: I recommend reading my tutorial on drop shoulder sweaters before selecting this construction.
Here are two designs in both set-in sleeve and drop shoulder constructions. Firth:
And Catboat: