The material is a course blend of medium-length fibers of secret origin, created using a custom-built multi-stage blending machine that is secretly located in the basement of an undisclosed warehouse somewhere in the central part of the Arizona Sonoran Desert.

Simi Seal is the exclusive material used to tie the world-famous Simi Seal Leech. This material can also be used in a variety of dubbing applications, from nymph patterns to medium-sized streamers. The coarse fibers produce a bushy dubbing that can be used to build large bodies, or it can be vigorously brushed out and trimmed or left long.