The widths are cabinet widths
61x22, 49x22, 37x22 and 31x22 lead the sizes here, with a set of single figures behind them.
Those first numbers are the standard vanity widths, and the 22 is the depth from wall to front edge. A top is made for a cabinet rather than for a room, so the search starts at the cabinet. Vanities, single vanities and double vanities carry the cabinets.
Engineered marble leads the materials
Engineered marble is the largest material here, then quartz, granite, natural marble and a wood.
The first two are manufactured: crushed mineral bound in resin and pressed into slabs. That matters on a vanity top because it repeats exactly, so the top matches its own splash and a second top in a double bathroom matches the first. A natural stone top and its splash come from different parts of a block and can differ visibly.
Twenty millimetres, almost throughout
Most of this range is 0.79 inch, which is 20 millimetres, the standard slab thickness these are cut from.
That figure is what a vanity top looks like from the side, and it is also the depth the splash will stand off the wall. Where a mirror, a cabinet or a light sits directly above the counter, it is worth knowing in advance. Vanity backsplashes covers the splash.
The cutout is already made
A vanity top arrives with the basin opening cut and the faucet holes drilled, which is the difference between this and buying a slab.
It also means the basin and the faucet are decided by the top rather than after it. A top drilled for a single hole faucet will not take a widespread set, and an undermount cutout will not accept a drop-in basin. Those are the two things to check against the top before anything else is ordered.
Polished, with a little gloss
Polished covers almost this whole range with a small glossy group.
On a bathroom counter that is the usual answer: a reflective surface is easier to keep looking clean, it brightens a room that frequently has no window, and on an engineered material there is no reason to avoid it. A honed top is a natural stone decision rather than an engineered one.
One top or two in a double bathroom
A double vanity can take one long top with two cutouts or two separate tops set side by side, and the sizes here support both.
A single 61 inch top gives an unbroken surface with no join in the middle, which is why most people want it. Two smaller tops are easier to carry up a stair and through a doorway, which is why they still exist. The join is the whole of the difference, and on a manufactured material it is far less visible than it would be on a natural stone.
White carries the colors
White is well ahead, then beige, gray and brown, with Calacatta, Carrara and Argento among the series names.
Those are marble names on manufactured products, which is what most engineered marble is doing: reproducing a white stone with veining, consistently, in a format cut to a cabinet. Marble sinks is the quarried alternative for the basin itself.