NinestarsDZT-12-9, 15.2" Stainless Steel Automatic Sensor 3.2 Gallon Garbage Disposal, Plastic lid

The product description is for some 0.5 Gal container, not for a 3.1 Gal trash can! Is this, in fact, the 3.1 Gallon trash can?

Does this have an interior pail- so it could be used bag free? Or does it require a bag to catch items?

Can you keep the lid open for extended amounts of time?

I want to put this under the kitchen sink, behind the door. Will the presence of the door cause it to open?