Serial Number for most recent SR9 update?

[SS2245]

I plan to purchase the SR9. Would like to be sure that it's the most recent version. What serial# should it be??
Many Thanks, Steve

 

[Egalloway]

Look for serial number prefix starting with 331. Also check to see it has the D shaped mag release button. Some 331 units still have the round release and can have a toss up in the internal fire control components. One of my test pistols is came this way. 331-xxxxx round release, short striker spring, new stlye reset bar, long indicator, old plunger style and spring. Real mutt. All the D shaped 331 units have the current parts.
Eric