This is all the info I could find, no web address though.
Rhino Chokes
21027 NE Highway 27
Williston, FL 32696
Tel: 800-226-3613 352-528-6110
Fax: 352-528-4111
[email protected]
Est: 1984
Contact: Janet or Joe Morales
The Rhino Choke was awarded a Patent in 1994 for its unique internal structure and finish plus elongated ported design. No other production choke can outperform them! The Ports serve TWO PURPOSES: First, they cause suction on the wad, pulling it away from the shot stream before it collides with it causing 'flyers' in the pattern, Second, the byproduct of additional holes past the end of the barrel is added muzzle jump and recoil reduction, enough that it is noticeable. Made of high grade stainless steel that will not rust or corrode, no wrench needed. Call for prices and models.