The WITT Naughty 9 is a 9mm ultra compact suppressor, 4 inches long and machined from 416 stainless steel (brand part no. 9CSBLK). It is the larger-bore member of Witt Machine’s Ultra Compact Suppressor family, following the Canooter Valve and the Dirty 30, and WITT pitches it at the MPX, the pistol-caliber carbine and the truck gun. The body is 1-5/8 inches across, and WITT designed it with no blowback through the charging handle. It is rated for full auto with no barrel length restriction and is designed for fixed-barrel applications. WITT offers it in 1/2-28 and 5/8-24 threading.

Key Specifications

• The caliber is 9mm, the round behind the MPX and most pistol-caliber carbines.
• Overall length is 4 inches, compact on a short carbine.
• Diameter is 1-5/8 inches, a stout body for a pistol-caliber can.
• The material is 416 stainless steel, a durable steel for repeated use.
• WITT makes it in 1/2-28 or 5/8-24 threading, the two common 9mm muzzle threads.
• WITT lists it as full auto rated with no barrel length restriction.
• It is designed for fixed-barrel applications, with no blowback through the charging handle.

Frequently Asked Questions

Will the Naughty 9 fit my MPX? WITT describes the Naughty 9 as made for the MPX, pistol-caliber carbines and truck guns. It is designed for fixed-barrel applications.

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.

Which thread does it use? WITT offers the Naughty 9 in 1/2-28 and 5/8-24 threading.

Buy the WITT Naughty 9 9mm Ultra Compact Suppressor, 416 Stainless

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. Order through WITT‘s suppressors lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer. At 4 inches long, it keeps a 9mm carbine short and easy to handle.