The molding material comes...
The molding material comes in a tube that looks like a small caulking gun.
After about two minutes, the material is cured and can be removed from my ear, leaving no residue. At that point I get to chuck the Bite-Block into the trash can and the finishing process can begin.
Mark also manufactures a version of these ear plugs (PN MOS-R1) with a single transducer (mono) electronic packet with 24-inch mono cable. If you want to go for the radio version the only difference in the process is that prior to injecting the impression material into your ear, Mark will place the electronic packet in your ear. He also uses a different kind of material that is compatible with electronics, called Fit-Mold Premium. That material takes five minutes to cure and then it's finished, all in about an hour.
The product design allows under-helmet use for race applications and quite frankly works so well that you can hardly tell you've got them in there with your helmet on. Now the best part—these ear plugs provide noise reduction down to a decibel range of 27-32 dba. Considering that most race cars can produce noise well beyond 95 dba, ear plugs that bring the ambient noise down to the sub-30 dba level are priceless for saving your hearing.
These plugs retail for $185 and come with a 90-day warranty. At that price they're a can't miss addition to your safety equipment for this year's racing season.

As you can tell by the look...

As you can tell by the look on my face, this stuff feels weird when it’s piped into your ear.

As soon as Mark is finished...

As soon as Mark is finished piping the molding material into my ear, a Bite-Block is placed in my mount to prevent my jaw from moving around as the material cools.

In this close-up you can see...

In this close-up you can see how the material is piped flush to the outer ear. This allows the plugs to be worn under a racing helmet.

The plug is removed from the...

The plug is removed from the ear, leaving no residue at all.

You can really see the Oto-Block,...

You can really see the Oto-Block, that black plug-looking thing, in this picture.

The finished product. The...

The finished product. The two colors differentiate between the right and left ears.