Specializing in buffer tubes for AR-15-pattern rifles, Phase 5 also offers a myriad of additional products. One such item, the REVOsas, is a bilateral, swiveling, sling attachment point machined from billet steel. Designed to fit mil-spec buffer tubes, the unit ships with a castle nut for installation. Both items have a satin black Parkerized finish. Price: $65. Contact: Phase 5 Weapon Systems, Inc.; phase5wsi.com.