What bulb does it take?

Any E27 base bulb. An LED filament bulb in a warm color temperature gives the vintage look; a higher-lumen bulb gives more usable light.

The fixture has no dimmer of its own. Dimming works only if you fit a dimmable E27 bulb and control it with a compatible dimmer switch.

Can it be used in the US?

Yes. It accepts 110–240V, so it works on standard US 120V wiring. Have a qualified electrician install it and confirm local code.

The cable is about 95 cm, so the shade hangs within roughly that distance of the ceiling. That suits standard ceilings over a table or island, not tall vaulted rooms.

The pendant, the metal shade, the ceiling canopy and the installation hardware. The bulb is not included.

Is it bright enough for a whole room?

It is a single-bulb fixture, so treat it as task or accent light over a table or counter. For a large room, plan several pendants or add other lighting.