Solution for installation failure: The second small grill black piece is primarily a supplementary installation bar designed for certain models such as E10, X25, X20, etc., which requires the removal of the bottom plastic frame to withstand the invasion of large pieces of debris. You can search for 9991460-r1 on Youtube to obtain a video installation tutorial Filtration capacity:The 9991460-R1 ultra-fine filter basket can remove dirt and debris such as hair, dust, and diatoms from the swimming pool. The bottom spring filter can easily collect large objects such as leaves into the filter basket, improving filtration efficiency and facilitating removal Easy to clean:When cleaning, directly lift out the filter basket, which is simpler and more convenient. Generally, clean the filter every 4-6 weeks to achieve optimal performance. Durable and sturdy Durable and sturdy:Equipped with a complete ABS plastic frame, it firmly supports the filter layer, preventing it from cracking during operation. It is perfectly replaced with the original filter basket and can be used properly. These ultra-fine filters can last for 2-3 years Packaging includes: This set of products includes black trays and more than 4 ultra-fine filters, making it a complete ultra-fine filter basket that can directly replace the entire original unit Compatible models:Dolphin Robotic Pool Cleaners: Active 10,E10,Echo,T15,Proteus DX3,Saturn(new),Cayman,Escape,S50,Encore,Solo,Nautilus CC and Advantage.Remind:This part is not compatible with the Nautilus (old), Nautilus CC Pro, Nautilus CC Supreme Ultra-Fine Filter Basket Compatible with Dolphin Nautilus CC Robotic Pool Cleaners S50, S100, Active 10, Echo,Nautilus CC,Encore, Active Solo,Advantage,T15,Cayman,Escape,E10 fit with S50 Echo T15 T25 Proteus DX3 Saturn Cayman Escape Encore Explorer E20 Solo Advantage S100 Active 10 & 15 Nautilus CC