The Dy'on Black Difference Bridle was created for horses with problems on the first and second cervicals. It has a headrest and a browband made up of one piece to relieve the neck (1st and 2nd cervical vertebra). The unique under-throat system linked to the noseband of this bridle ensures that the headpiece rests behind the 2nd cervical vertebra (this under-throat must be well adjusted against the cheeks). 1/2’’ (13mm) underbarb. Please note, this Dy'on bridle is not suitable for horses that do not show any signs of problems with the 1st and 2nd cervical vertebra. Take advice from your veterinarian or osteopath.