Extend Swimming Time - The Solar Pool Heater is made of special material. The transparent blue cover absorbs heat through thousands of bubbles during the day and releases heat into the pool, thus allowing for longer swimming time. Let you enjoy a pleasant swimming time! Notice: bubble side is down when use, normal the bubble will be a little deflated before sun exposure due to the principle of thermal expansion and contraction Reduces Water Evaporation - Placing the pool solar heater over the pool when not in use minimizes water loss due to evaporation; helps conserve water and maintain pool levels Keeping the Water Clean: The Solar Pool Covers are very easy to install. Just place it on the surface of the pool according to the right size of the pool. This will prevent leaves and other debris from falling into the pool and keep it as clean as possible Easy to Cut: The solar blanket is suitable for all shapes of pools, the size of the pool cover is 12FT with 2'' extra. If your pool is irregularly shaped, you can cut it according to the size of your pool, as long as you have scissors, you can easily cut the desired size and shape High Quality Material: Heavy-Duty material with strong welded seams for long lasting use. It is recommended to use with VINGLI's pool cover reel, which will make the pool heater easier to put on and off. If there is any problem after arrival, please feel free to contact us