Comp-N-Choke Non-Ported ARC Series Stainless Choke Tube for 12 Gauge Beretta Optima HP.
 
Extended choke with extensively-tested design for improved patterning. Conical/parallel internal configuration.
Two large constriction markings on extended portion for easy identification.

Easy to install and remove with your fingers. No special wrench or tool required.
 
Total length is 4-1/16" (so you can tell which case they will fit in).
 
If you don't see what you're looking for in my store, contact me and I'll get it for you.