have no idea the diameter. It did not needed to be installed, I put it into the sink drain myself in one minute, which is what should be. Everything is fine.
Hello Beach and thank you for your interest in Moen products. The Moen Garbage Disposal Removable Splash Guard is not designed for the use of the Kenmore garbage disposal. Should you have any additional questions, please contact Moen directly at 800-289-6636. Our business hours are 9:00 a.m. - 5:30 p.m. Monday through Friday Eastern Time.