Samson Manufacturing Corp. Samson Tactical Accessory Rail System, Forearm, Fits Sig 556, 3-Hole, Free Float, Black STAR-SIG-556-3H Samson STAR SIG 556 handguards are a two-piece free-float design that is easy to install. Lightweight aluminum construction" features Picatinny rails at the 3" 6 and 9 o'clock positions. Fits the Sig Sauer 556" 556 Classic and 556R. Will not fit the Xi. This fits the Sig 556 (3-hole). Includes (2x) 2" rail sections and (1x) 4" rail section.