From Mike's website:
All of the pipes that I offer are hand carved and carefully crafted from top quality, air cured briar. They are designed to provide a lifetime of enjoyable smoking.
The draft hole is bored to 4mm for an easy, open draw, and is tapered and polished internally, the length of the stem.
Unless noted, all of these pipes will pass a pipe cleaner.
A thin layer of activated carbon has been applied to the tobacco chamber, using a natural binding agent composed of the same sugars in the proportions that are naturally found in pipe tobacco.
I believe this significantly aids the break in process, protects the briar during it's initial introduction to fire, and forms the foundation for a solid and even cake build up.
Contact information: E-mail: mailto:email@example.com ; Mike Brissett, 1000 South 114th Street, West Allis, WI 53214