The Rifle Length Mini Stock Assembly (RMSA) is a combo kit featuring Phase 5's Universal Mini Stock (UMS) and rifle length HexOne buffer tube for an excellent rifle fixed stock solution. The UMS is also compatible with a number of other buffer tubes, including Mil-spec carbine receiver extensions and most round tubes, it was designed to complement the sturdy HexOne buffer tube. It is precision machined in house from USA sourced raw billet aluminum. The HexOne buffer tube is cut from 7075-T7 and the UMS is 6061-T6. The buffer tube features a hexagonal design that is much thicker and rugged than a mil-spec receiver extension tube making it perfect for any of your rifle length AR platform systems. The UMS offers a smaller footprint and bottom curve which makes for a far superior anchor of the stock on the chest. This allows an operator to get in and out of position with greater of ease.The Phase 5 Rifle Mini Stock Assembly (RMSA) is a combo kit featuring our Universal Mini Stock (UMS) mounted on our HexOne Rifle Length buffer tube (HexOne-R). This pair is an excellent fixed stock solution. The UMS and HexOne-R are precision machined in house from USA sourced raw billet aluminum. The HexOne-R buffer tube is cut from 7075-T7 and the UMS is 6061-T6. The HexOne buffer tube features a hexagonal design that is much thicker and rugged than a Mil-Spec receiver extension tube. The UMS offers a smaller footprint and bottom curve which makes for a far superior anchor of the stock on the chest, and this allows an operator to get in and out of position with greater ease. The HexOne and UMS undergo a rugged tumbling process that further strengthens the exterior of the parts while leaving the surfaces smooth and snag free. Features: Heavy-duty fixed mini stock assembly Proudly made in the US, from US sourced raw billet aluminum, on US manufactured machines Rifle length buffer tube that accepts any end plate sling mount