The Irregular Design Group Hesychia 556UK is a dedicated 5.56mm duty suppressor built by a team with Tier 1 special operations roots, and it’s made to keep up with short, hard-working rifles. The can is 3D printed as a single monolithic unit from Inconel 718 using Laser Powder Bed Fusion, giving you a sealed one-piece core with no baffle stack or internal parts to loosen. At just 4.75" long and 13 oz, it keeps an SBR or carbine short and balanced, and its low back-pressure design cuts the gas and concussion that reach the shooter. On a 10.3" MK18 test host, IDG measured 135 dB at the ear and 138 dB at the muzzle.

The 556UK uses IDG’s patented Hesion Bow Dual-Lock Mount. A 15-degree taper and a 1 1/8"-8 left-hand buttress thread provide the primary lock, sealing gas and holding alignment with minimal rotation. Six flexure pawls printed into the suppressor body engage 32 grooves on the muzzle device for built-in redundant retention, with no separate sleeve or latch. This bundle includes IDG’s Micro Flow Enhancer in 1/2"-28, the recommended choice for a rifle that will spend most of its life suppressed. It works as the suppressor’s first stage of gas control to get the most out of the can. Full-auto rated on barrels 10.3" and longer and finished in OD Green Cerakote, the Hesychia 556UK is a compact, duty-grade can built to protect the shooter as much as it quiets the shot.

Key Features:

• Manufacturer: Irregular Design Group (IDG)
• Model: Hesychia 556UK + Micro Flow Enhancer Bundle
• Product Type: Rifle Suppressor
• Caliber Rating: 5.56mm NATO
• Full Auto Rated: Yes (10.3" Barrels and Longer)
• Minimum Barrel Length: 10.3"
• Sound Rating: 135 dB at Ear / 138 dB at Muzzle (10.3" MK18)
• Material: Inconel 718
• Construction: Monolithic, Laser Powder Bed Fusion (3D Printed)
• Mount: Hesion Bow Dual-Lock Mount
• Muzzle Device: Micro Flow Enhancer, 1/2"-28 (Included)
• Overall Length: 4.75" (Adds 2.6" with Muzzle Device)
• Diameter: 1.75"
• Weight: 13 oz
• Finish: OD Green Cerakote
• NFA Item: Yes
• What’s in the Box: Hesychia 556UK Suppressor, Micro Flow Enhancer 1/2"-28 Muzzle Device

Please Note: The Hesychia 556UK requires a minimum barrel length of 10.3". Install the Micro Flow Enhancer at 30 ft-lbs. No timing is required. On a new system, cycle the mount on and off 5 to 7 times before firing.