With anatomical occlusal surfaces and tooth-shaped cross-sections (not cylindrical!), they’re much easier to adapt to the preparation . . . without time-consuming axial shaping.
The larger sizes measures a full 11mm, so you’ll have plenty of crown to cover and protect the margin.
They come in nine sizes for molars and bicuspids, coded to the standard copper-band numbering system. The intro kit includes a compartmented tray makes selection easy. And each crown is stamped with the size and quadrant to avoid confusion.