Maytronics 9301PRO Dolphin Pro In Ground Robotic Pool Cleaner cleans the floor, walls and waterline of pools up to 50 feet long with ease. It features an extra large filter surface to ensure your pool stays crystal clear. The Dolphin Pro's built-in impact sensor recognizes and avoids walls or other obstacles to ensure a deep clean. Our robotic technology has reduced cleaning time to 3-5 hours which will also help to reduce your chemical and electricity costs.