The Radical Defense LS5 FDE is a 5.56mm rifle suppressor finished in Flat Dark Earth (brand part no. LS5-FDE). Radical Defense designs the LS5 for 5.56mm weapons, with M4A1, MK18 and IAR platforms named as the target hosts, and describes it as suited to both semi-auto and full-auto applications. Its Breathable Technology actively stabilizes internal pressure, which cuts blowback and carbon buildup at the action. The monolithic, corrosion-resistant body mounts on a 1.375-24 hub interface with a KFM flash hider threaded 1/2×28, the standard AR-15 muzzle thread. The tan finish suits an FDE carbine.

Key Specifications

• The caliber rating is 5.56mm, the chambering most AR-15 and M4-pattern rifles use.
• Radical Defense names M4A1, MK18 and IAR platforms as hosts, the carbines and automatic rifles the LS5 was designed around.
• Length is 7.5 inches, a size that works on both carbines and rifle-length 5.56 hosts.
• Diameter is 1.75 inches, the tube size to check against your handguard.
• The attachment is a 1.375-24 hub mount, the rear interface that locks the suppressor to its muzzle device.
• The muzzle device is a KFM flash hider threaded 1/2×28, the standard 5.56 AR-15 muzzle thread.
• Gas management is Breathable Technology, which reduces blowback and carbon buildup at the action.
• The body is monolithic and corrosion resistant, built for salt air, extreme temperatures and prolonged fire.
• The finish is Flat Dark Earth, a tan color for FDE builds.

Frequently Asked Questions

What color is this LS5? Flat Dark Earth, a tan finish that matches FDE rifles and furniture.

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for suppressors. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply.

Does the LS5 work on full-auto rifles? Radical Defense describes the LS5 as suited to both semi-auto and full-auto applications.

Buy the Radical Defense LS5 Suppressor, 5.56mm, FDE

As of October 9, 2026, this suppressor transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Thread a KFM flash hider onto a 1/2×28 barrel and the tan can goes straight on. Order through Radical Defense‘s silencers and suppressed firearms lineup and our Lubbock, Texas team will handle the transfer.