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.