Astro 326P 3/16" Stroke Heavy Duty Quick Change Random Orbit PSA Palm Sander, 6" Quick-Change front mounted locking button requires no tools to quickly change out backing pad Extremely durable design with high quality machined components 3/16" Random Orbit for a professional finish High power, low air consumption Includes 6" Polyurethane PSA backing pad; Can be used with 5" or 6" backing pad