The conventional designs are two: conical or conical-parallel. And that’s it. All choke tube manufacturers produce chokes following one of them, no exceptions at all. Some state that their chokes perform “better” than the others because of their “special profile” or “geometry”, but without saying how or where they differ from all the rest. They are just declared…“better” (and some even “The best in the World”!).
But measuring with the proper instruments one can see that ALL are exactly the same. Whenever you conduct a pattern test with multiple choke brands and look at the pattern with the brand names hidden, you will see that it will be impossible to say which choke was used every time because they all pattern pretty much the same, none will stand out. It’s just common advertising hype. Just take a look at the special forums.
The BRAIN Choke Tubes are the only ones having the unique, innovative “CHOKE – in – CHOKE” design that diversifies them from all the conventional ones by producing perfectly uniform patterns.

Wad retarding is known since late 1800s. The modern application in the form of interchangeable tubes does not change this design into an innovative one. But, as happened in the beginning, the modern versions proved lesser compared to constriction designs.
The protruding studs inside them destroy the peripheral pellets and require special wads, excluding completely the use of felt wads. 

Because, if you want to be the best, you have to be in all aspects, no shortcuts allowed. Our two materials may be much more expensive even than all the others but they are stronger and harder than any other similar material.
And the costly Stress Relief procedure drives them to unmatched levels of interaction with the load as it passes through and keep them safe against future dimensional alterations.

In metallurgy, engineers consider hardness and two types of material strength: yield strength and ultimate strength. Our two materials have hardness 480 Brinells, yield strength 150,000 psi, and ultimate strength 200,000 psi. The pure aluminum is really very weak and soft malleable material. But even the strongest, hardened “aerospace” aluminum alloy has hardness 150 Brinells, yield strength 60,000 psi, and ultimate strength 80,000 psi. i.e. all less than half compared to our materials! Yes, airplane cabins are made of aluminum alloys but they have to deal with…air, not with hard hammering spheres of lead or steel!

They don’t! First of all, the Pre-Choking section constitutes a new entrance diameter to the final choke, forming its own accurate “bore to choke” relevance, something that eliminates bore diameter differences between barrels of the same make. The bore of the barrel is no more the starting point to calculate choking as with conventional design chokes.
Besides, each BRAIN Choke Tube covers a wider distance spectrum than its conventional “equal”, being effective at the same time in both closer and longer distances than this. That’s why you need less BRAIN Choke Tubes to cover completely your entire shooting range

It must be pointed out that every choke will produce various patterns even with shotshells from the same box. The always existing slight variations from shotshell to shotshell in powder weight, closure pressure, primer power etc. are sufficient for pattern variations. The same, in larger scale, may happen with shotshells of different makes or types etc. Therefore, to say that a choke is good, better or…best, someone must shoot a lot with it, using all kinds of ammo he uses mostly and then compare the average pattern with others. If he compares just one or to two patterns from each using one type of shotshell then, the comparison most probably will be completely false and deceptive.
BRAIN Choke Tubes are the best in the World by far and this is proved in ALL the comparison tests conducted by numerous Shotgun Experts.

After some hundreds of shots, if your ammo’s powders do not give “clean” burning, you may see some carbon fouling hidden inside the Expansion Section step ring. Even so, the BRAIN effect is still there for you but, for optimum performance, we would suggest you to clean this spot periodically or before an important competition etc, by rotating your cleaning rod with a metallic brush inside the choke.