the new benelli m2 and sbe 2 and im not sure what othe rmodels use those new Crio + choke tubes. its the way they make the barrel so they use new chokes, not the traditional benelli/beretta choke. most packages with the Crio + chokes will say Crio + or SBE II on them. so your friend is right. i had the same problem when i bought the first choke for my SBE 2 but i just sent mine back for an exchange.