Thank you all for your prompt and insightful posts. Is there any thought that the "small" rear ghost ring is unnecessary? If so, perhaps I should only replace the front post. Your thoughts?
Does anyone have any experience or a recommendation for a tritium sight for a Benelli M1S90? (I just installed the TruGlo TFOs on my Glock 22--they are OUTSTANDING !) I'm not sure if TruGlo offers TFOs for shotguns. My Benelli has a foreend Surefire light. This weapon is used strictly for HD and/or patrol.