One of VLTOR’s most innovative products is the Versatile Interface Structure (VIS) upper receiver assembly. The VIS is a polylithic upper receiver assembly that ties the normally individual receiver and handguard into a single, aggregate part. This combination overcomes many problems that are associated with the traditional “two piece” design; most notably the greatly improved structural strength and repeatable accuracy. This affords the user all the benefits of a free-floating barrel and solid railed forend. Note: The VIS comes supplied with the stripped upper only. The barrel, sights, and all other accessories must be purchased separately.