One or two rows of curved tines.
Can be used one against the other (one in each hand), or with one mounted on a base (fastened to a table or some other object).
Two or more rows of straight tines.
One comb must be mounted in clamp to a table, and the other is worked against it to transfer fiber from the stationary comb to the moving one.
significantly smaller and lighter than English combs.
Designed for hand use with small amounts of fiber.
Make your own combs: http://blog.loxosceles.org/posts/1147125661.shtml