Air
Home to the world's quietest airgun moderators, plus precision pellet caddies, self-healing targets, chassis parts, and shooting accessories, all designed and manufactured by Silent Thunder Ordnance. From the Accipiter and Sarissa lines to the Pocket Benchrest and Eyeshine Targets, this is the full catalog of STO air products built for performance and tested before they ship.
Brevitas II
Brevitas II
The Brevitas II is our smallest moderator, coming in at 28x70mm and under 25 grams. For reference, that's roughly the size of a fat tube of chapstick. These are not typos. At this size, the design goal was never whisper-quiet performance; it was to produce the most effective sound attenuation physically possible in a package that disappears onto the end of a shrouded rifle.
The design uses Nikola Tesla's Gas Diode to reflex propellant air back on itself, resisting forward flow through geometry alone with no moving parts. Multiple compact gas diode stages are packed into the available length, followed by a damping section that substantially reduces post-peak noise, a meaningful addition at this size. A whoosh on firing is still a consequence of the micro-size form factor, but it's considerably quieter than earlier versions. What the Brevitas II delivers is real peak attenuation in a package that disappears onto the muzzle. Pair it with a shrouded rifle and it takes full advantage of the barrel's unused reflex volume for even better results. If you need more attenuation than that, you need a larger moderator.
The Brevitas II is the successor to the original Brevitas, which was produced in limited numbers before manufacturing constraints forced a pause. The successor solves those manufacturing issues while improving on the original's acoustic performance, squeezing more out of an already extremely constrained form factor.
Key Features:
Tesla Gas Diode design: Multiple compact diode stages reflex and delay propellant air through geometry alone, no moving parts
Extreme compact form factor: 28x70mm, under 25 grams; designed to blend into the shroud profile of a shrouded rifle
Shroud-friendly design: Performs best paired with a shrouded rifle, using the barrel shroud's reflex volume to extend dwell time and maximize attenuation, but delivers meaningful peak reduction on unshrouded guns too
.30 caliber bore fits all standard smallbore airguns: Testing showed no performance improvement from smaller bores, so these ship bored for .30 cal and run cleanly from .177 through .30
Compact damping section: Rev.2 adds a damping stage after the diode stack, substantially reducing post-peak noise without growing the form factor
Built and tested in the USA
This product is intended for airgun use only. Use of this product in any manner inconsistent with its design intent is a violation of federal law. More information about the federal court ruling which clarified the legality of airgun moderators in the United States can be found here. Local restrictions may still apply. It is the responsibility of the buyer to ensure compliance with all applicable laws.
This item ships within the United States only.
Sound Profile Data
A note on reading these traces: peak alone doesn't tell the full story. Post-peak sound character has a substantial effect on perceived loudness, often more than the peak value itself. Each trace is provided so you can evaluate the full sound profile rather than a single number. Note that traces are not shown to the same scale.
Brevitas Rev.2, as tested on a shrouded FX Crown .30. Average peak 443.52.
Rev.2 of the Brevitas offers an improvement in peak suppression, however far and away the biggest improvement is in the post-peak sound signature. This is due to enhanced damping architecture which eats up more of the noise created by tiny little diodes struggling mightily to hold back so much air. To the human ear, the rev.2 sounds noticeably quieter due primarily to this effect.
