This high-quality double-jointed bustrens is made of solid Cuprigan with stainless steel rings. Cuprigan is an alloy consisting of 89% copper, 7% aluminum, 3% iron and 1% zinc The oxidation process of the material gives a pleasant smell and taste. The anatomical shape follows the shape of the horse's mouth, creating a soft and even pressure distribution. Due to the combination of the design and the unique composition of Cuprigan, the chewing process and saliva formation is stimulated, which can create a fine connection with the sensitive horse's mouth. The bit has a gentle effect on the mouth. The nozzle has a thickness of 12 mm and the oval bit rings have a diameter of 55 mm.
A bustrens has rings that cannot rotate freely, so aids act more directly. This type of bit is generally well accepted, because the mouthpiece is relatively firm in the mouth.
With a double-jointed bit, the mouthpiece consists of three parts. The middle part of the mouthpiece lies flat on the tongue. This creates more pressure on the tongue than with a single broken mouthpiece. The thicker the middle part, the more pressure on the tongue.