I need to know the exact dimensions (inner diameter, outer diameter, thickness) of the handguard O-Ring of the Beretta Xtrema 2 (piece #22). I'm stupid and it fell out of the handguard when I was disassembling it out in a field and I need to replace it in the next few days so ordering the part online is out of the question, have to get it at a hardware store or something but I can't for the life of me find the dimensions of the part online.