This is the YHM Fat Cat 5.56 suppressor in its Cat’s Ass end cap version, the alternative Yankee Hill Machine offers to the standard end cap on its compact 5.56 NATO can (brand part no. YHM-2210-MB-28). The Fat Cat uses baffle geometry designed to reduce blowback, and its 1.94-inch diameter gives the gas more internal volume for a lower, more pleasant tone. The body is heat-treated 17-4 stainless steel with a Cobalt 6 blast baffle, threaded to the 1.375×24 HUB pattern. It comes with an sRx Q.D. adapter, an sRx 1/2×28 Mini Q.D. muzzle brake and two suppressor wrenches, so it is ready to mount on a 5.56 carbine. Yankee Hill Machine notes it is a full inch shorter than its Turbo K with the adapter installed.

Key Specifications

• The end cap is the Cat’s Ass end cap, the alternative YHM offers to the standard end cap on the Fat Cat.
• The caliber rating is 5.56mm, the round this compact can was designed around.
• Length is 4.25 inches, or 4.50 inches with the sRx adapter, which keeps a carbine short.
• Weight is 11.2 ounces, or 13.2 ounces with the adapter, light for a rifle can.
• Diameter is 1.94 inches, wide enough to add internal volume for a lower tone.
• The body is heat-treated 17-4 stainless steel, an alloy chosen for rigorous use.
• The blast baffle is Cobalt 6, a hard alloy that takes the first impact of the gas.
• The rear thread is 1.375×24 HUB, so it also works with HUB-compatible mounts.
• Yankee Hill Machine publishes a 139 dB decibel rating for the Fat Cat.
• It is full-auto rated, with a 10-inch minimum barrel length for 5.56 NATO.

Frequently Asked Questions

What is different about this Fat Cat? It carries the Cat’s Ass end cap. Yankee Hill Machine sells the Fat Cat with either a standard end cap or the Cat’s Ass end cap, and the rest of the suppressor is the same.

What comes in the box? Yankee Hill Machine ships the Fat Cat with an sRx Q.D. adapter, an sRx 1/2×28 Mini Q.D. muzzle brake and two suppressor wrenches.

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.

Buy the YHM Fat Cat 5.56 Suppressor with Cat’s Ass End Cap

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 Yankee Hill Machine‘s silencers and suppressed firearms lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.