I have a similar-looking composter. Mine was referred to as "the Cadillac of composters". I've had it a good 20 years and it works pretty well. It's difficult to get all of the finished compost out through the doors, but I occasionally empty it all out and start again.
As others have said, it's a good idea to have a pile of dried leaves to add occasionally. They also keep down the fruit flies in late summer!
I love to recycle, and I sometimes pick up leaves after others have raked, bagged them, and left them curb-side.
Linda