Ballistic Specialties in Batesville, AR. I believe they have a website and still in biz. I may be wrong but think that Rob Roberts used to work there.
I have a Ballistic Specialties choke for a Mossberg 835 that has a wonderful pattern...not extreme tight 10" numbers but very , very even pattern in 20", for that reason I am letting my 13 year old grandson use this season.