These are 1″ brushes with wooden handles. They are great for casual bookbinding and inexpensive enough to consider disposable. Also perfect for painting.
Sally Monahan has a great tip for us: Buy 2 brushes and cut the bristles on one down to about 1″ long. Now you have a short, stiff brush for pounding glue between signatures as well as your longer-bristled, general purpose glue brush.