 The design is based on an early 7.62×51mm NATO prototype of the FN Minimi, modified to be a scaled-up version of the 5.56 mm Mk 46 Mod 0.Being heavily based on the Mk 46 Mod 0, the Mk 48 Mod 0 features five MIL-STD-1913 Picatinny rails (one on top of the receiver, one on each side of the forearm/handguard, one under the handguard, and one on top of the barrel), an integral folding bipod, and a tripod-mounting lug.The weapon is fitted with the same fixed, polymer buttstock as the M249, although the metallic, collapsible buttstock from the "Para" model can be found in some models.