There are different types of 16x25x1 furnace filters, though they all have the same size. They mainly differ in their MERV rating, which shows how well they capture airborne particles. Common types are standard fiberglass filters (lower MERV), pleated filters (higher MERV), and electrostatic filters (often the highest MERV). When choosing a filter, consider your air quality needs, allergies, and your furnace's requirements.