Do I need a compressor to use it?

Yes. It needs an air compressor that provides at least 4 kg of air pressure. The compressor is not included, so factor it in before buying.

What can the twin pens do that one pen cannot?

The two pens let you polish equipment of different hardness without changing the setup. That saves time when you move between delicate and tougher pieces.

How big is the working opening?

The operating space has a diameter of 16.9 inches. That is enough for jewelry, relics and dental devices, but not for large or bulky parts.

Is it good for jewelry and dental work?

Yes. It is aimed at polishing jewelry, relics and dental devices, where fine control matters. The foot pedal and clear window help with small, detailed pieces.

Does it come with abrasive?

The listing does not state what abrasive is included, so plan to buy media separately. Check the cabinet's needs before your first run.

How does it compare with a single-pen cabinet?

It gives you two pens for different hardness levels in one cabinet, which single-pen units lack. In exchange, it is a budget machine and expects a capable compressor.