MILLER FORGE DOUBLE DUCK SNAP ON COMB 4. This electric clipper attachment is for use on the larger, professional clipper units made by Andis, Oster, Wahl, or Laube and most commonly is placed on the #10, #15,#30, or #40 clipper blades. When used on a well brushed out coat, leaves a hair length up to 3/16 inches long. This is a rocker bottomed comb that can subtly vary the hair length depending on the back and forth rocking of the clipper unit and has a front to rear, spring loaded attach action.