Like it or not, grease happens. Right over your head, right now: Fats, Oil and Grease (FOG) may be destroying your roof and creating a real fire hazard. And after it’s done there, FOG will typically make its way into your drains, creating even more problems for you. With more cities and states passing legislation aimed at protecting storm drains, you may be liable for expensive fines. With the revolutionary Grease Catcher Grease Containment System, you can defend your kitchen roof from damage or fire by automatically catching and absorbing grease and oils that drip from your kitchen exhaust fan. The Tray Grease Pillow keeps grease from leaching out when soaked with rain or snow. It's light weight, hydrophobic and easy to replace. Pillows are 16" x 16" Case of 2 Pillows. For use with G5000 (Grease Catcher Tray)