Cover Rollers: This is a tool designed to roll-up and easily store a pool cover. Leaf Nets:The cover is specifically designed to keep leaf and plant debris out of the pool water. Liquid Cover: The cover contains a liquid that forms protective layer on top of the pool. These types of covers are also solar covers. Safety Cover: This is designed to keep people out of a pool. The construction will be very durable and the cover will be rated for at least 485 Lbs of pressure. Solar Covers: The cover is intended to heat the pool with solar energy and trap heat overnight. Winter Covers: The cover is intended to cover and protect the pool throughout the winter months. These covers tend to be much thicker than others.