I'm glad that you posted that second response. Please please please please don't chuck a piece of equipment on a horse just to strap its head down to make it 'look pretty'. A 'head set' comes only from correct work from the hindquarters of the horse, a swinging back and eventually the 'head set' will come naturally.
Have you got a trainer? Because I am a strong believer in fixing the root of the problem, not just covering it with a bandaid. If he is throwing his head constantly, there will be a reason for him doing so. Possible dental issues, bitting issues, and rider issues. I would eliminate all of these options before strapping something to his head to cover the problem.
Yes sorry everyone that I posted the first one I reliezed that sound very stupid:( But kayty I know for a fact that there is no problem with him that causes him to throw his head. He is a very funny, always energetic horse and he throws his head for fun! Please dnt say that a horse doesn't do that without a problem because this horse does. When I'm riding him hands in correct position everything is fine.. He joyfully throws his head. But now it's not funny anymore because I don't want him to do that in a show ring. SO I need a martingale.! Posted via Mobile Device
Even with everything you've said here horse lover, i'd still go with what kayty says and work with a trainer to teach your horse to use himself properly. I fully believe that a happy healthy horse doesn't "joyfully" throw his head all the time. Once in a great while? Sure. There are always exceptions. But often enough that you want a piece of equipment to help "solve" the problem? No.