The Pre-Filter Net can be used on all basket skimmers up to 24cm in diameter, with or without handles. It retains dirt and rubbish (leaves, twigs, insects, etc.) which accumulate on the water surface. It simplifies the tedious job of cleaning the basket and protects the pump. Its patented double fixture system: fastener and elastic, plus specialized netting of 250-300 microns guarantee optimal results. It has much finer netting than the basket skimmer, more particles are retained so the main filter requires less backwashing. Further, far less chlorine and other chemical products are needed as levels of dirt and rubbish become minimal. Thanks to the fastener, dirt and other waste materials are prevented from going back into the pool when the pump is stopped.