"Rooms by the Sea" is an oil painting. If you're asking what BRANDS of materials he used, I'm not sure that question can be answered. I just flipped through my Hopper bio and there was no mention of any paint or brush preferences he might have had.
Other than paints, he'd have used everything else you'd need to produce an oil painting---a wooden stretcher, canvas, ground (a primer, which in those days might have been white lead), brushes, rags, turpentine, linseed oil, palette knives and a palette.