Aeropress Rubber SealAfter making hundreds or even thousands of cups of exquisite coffee, the Rubber Plunger can become a little compressed or worn, allowing some air leakage around the edges. Be environmentally responsible by rehabilitating your AeroPress instead of throwing it away and starting over! Just pry off the tip with a little elbow grease and put on the new one. Its quick, easy, and amazingly effective.