SELF-ADJUSTING TURBINE VANES: All the POOLCLEANER™ cleaners have the patented self-adjusting turbines, which maximizes the power from the water flow. This turbine is similar to a paddle wheel with blades that are adjustable. This feature allows the POOLCLEANER™ to still move at low suction and low pressure. In addition, the folding vanes of the turbine allow for the easy passage of larger debris through the cleaner. STEERING SYSTEM: The 2x Suction POOLCLEANER™ has an internal programmed steering system that causes the left wheel to periodically reverse, allowing the POOLCLEANER™ to turn and then move in another direction. For the 2x Suction POOLCLEANER™, there are five different programmed turns ranging from 90 to 450 degrees. This feature allows the POOLCLEANER™ to cover not only the deep end, but also the shallow end. The POOLCLEANER™ has no problem with uneven surfaces or strange shapes. It wont stick in a corner or get hung up by a main drain. ROBUST TIRE TREADS: One look and you will see that the patented tire treads give the POOLCLEANER™ better climbing ability and ostacle maneuverability. The tires come with tread wear markers that show you when to replace your tires. The front tires of the POOLCLEANER™ have humps (raised treads) that allow the POOLCLEANER™ to overcome any reasonable obstacles such as the main drain and uneven surfaces. This makes the POOLCLEANER™ ideal for all pool surfaces and shapes. ADJUSTABLE SKIRT: The POOLCLEANER™ has patented adjustable skirts that allow the cleaner to maintain optimal suction under the machine even when it encounters obstacles. When the POOLCLEANER™ encounters an obstacle, one (or more) of the skirts will lift up (adjust) over the obstacle while maintaining suction under the cleaner.