If you have an Aquascape Signature Series 400 pond skimmer, this filter mat is exactly what you need for maintenance! It's specially shaped to fit perfectly in your skimmer unit, measuring 14x17.5x1.5 inches. The green filter material effectively catches debris and gunk from your pond water, keeping it cleaner and clearer. What's great is how easy it is to maintain - when it gets dirty, you just rinse it out and put it back in. It's completely safe for your fish and plants, no chemicals or anything harmful. Regular replacement of your filter mat helps your entire pond filtration system work more efficiently. The quality matches the original Aquascape standards, so you know it'll perform well. Keeping your filter mat clean means your skimmer can do its job properly, pulling leaves and debris from the water surface before they sink and decay. Your fish will appreciate the cleaner water, and you'll spend less time manually cleaning your pond. It's one of those simple but essential pond maintenance items that makes a big difference in water quality. Stock up so you always have a fresh one ready when needed!