Revo 2.5 & 3.3 nitro RC air filter was completely redesigned. We increased the surface area as much as possible allowing for even better breathing and less clogging. This RC air filter has a new very fine micron opening that keeps out dirt better than ever before. Our plastic is specially formulated exclusively for Motor Saver air filters for extreme lightness.We made a spring-loaded bracket that allows the air filter to be taken off and on very easily. The new Revo, RT80, nitro RC air cleaner has two body clips: one to hold bracket on and one to hold the air filter tightly together.