Introducing the B5 Systems Enhanced Sopmod Buttstock. The NSWC CRANE developed Sopmod Buttstock was born from the unique needs of Special Operation Forces. B5 Systems has taken the venerable design of the Sopmod Buttstock and incorporated the features sought by military professionals and firearm enthusiasts. Building upon its exceptional cheekweld and storage capbilities the B5 Systems Enhanced Sopmod Buttstock features an ambidexturous quick disconnect sling swivel mount, color matching hardware, and construction of milspec materials and finishes.