Rest assured that your choice of this Duststop fibreglass hammock filter is the right one for you. The continuous strand spun fibreglass, with oil coating, captures particles as air passes through your furnace. You can easily cut it to size and fit like a pro, from our 30” x 32” pad. Each new filter installation delivers 30 to 90 days of reliable performance. Imagine enjoying trouble-free air conditioning and central heating when you replace your filters regularly with a Duststop hammock furnace filter.