For casual sketch artists and note-takers, the Adonit Pro 4 is a low-maintenance, low-cost device for people just getting started with using a pen on a glass surface. The conductive precision disc is transparent, so the Adonit Pro 4 tip does not block off your view of what you are writing or drawing.

Source: Looking for a stylus for cheap? The Adonit Pro 4 is a great starting point