Package includes: two 09985 sealing ring washers and overpressure plugs. Compatibility: For Presto 0174510 (16 quarts), 0175107 (18 quarts), 0.175510 (16 quarts), 0178107 (23 quarts), 0178209 (23 quarts), 0178410 (23 quarts) Warm tip: The sealing ring of the pressure cooker may shrink, harden, deform, crack, wear or dent after being used for a long time. It should be replaced immediately. It is recommended to replace the sealing ring once every two to three years. Function: The sealing ring 09985 is installed around the inner edge of the cover and forms a solid pressure seal between the cover and the pressure cooker body during canning and cooking. High quality: Our 09985 sealing ring is made of food-grade silica gel, which is heat-resistant, non-toxic and not easy to be deformed by heat, and has good quality, Please rest assured to use it. Package includes: two 09985 sealing ring washers and overpressure plugs. Compatibility: For Presto 0174510 (16 quarts), 0175107 (18 quarts), 0.175510 (16 quarts), 0178107 (23 quarts), 0178209 (23 quarts), 0178410 (23 quarts) Warm tip: The sealing ring of the pressure cooker may shrink, harden, deform, crack, wear or dent after being used for a long time. It should be replaced immediately. It is recommended to replace the sealing ring once every two to three years. Function: The sealing ring 09985 is installed around the inner edge of the cover and forms a solid pressure seal between the cover and the pressure cooker body during canning and cooking. High quality: Our 09985 sealing ring is made of food-grade silica gel, which is heat-resistant, non-toxic and not easy to be deformed by heat, and has good quality, Please rest assured to use it.