Filet à aiguilles simple brisure features solid stainless steel washers and a soft iron mouthpiece with a "sweet iron" coating (blue). The soft iron coating on the mouthpiece stimulates salivation. When this material reacts with moisture, heat and air in an oxidation process, the surface rust has a sweet taste. This promotes acceptance of the bit. Eventually the blue color disappears, but the taste of the surface rust remains.
The anatomical design follows the shape of the horse's mouth, creating a smooth, even pressure distribution. The barrel of a single-break bit tilts at one point. It works on the tongue, bars, corners of the mouth and sometimes on the palate of the horse. If the reins are used, the bit takes on a V shape. As this bit has only one point of articulation, the tongue is freer than with, say, a double-broken bit. Barrel thickness 14 mm. Rings 65 mm.
The needle fillet has two rods, also called needles, located in front of the rings. The needles exert pressure on the cheeks, accentuating the steering aids and ensuring that the rider cannot pull the bit out of his mouth.