How do you get my horse's head down in western pleasure?

the thing u use 2 get a horses head down is a running or walking martingale

Edit: Please be careful when using these items. They can be very dangerous on a horse who is not used to having its head down. be gentle and gradual if using artificial devices to lower head carriage. My suggestion would be instead to just ride the horse constantly on a long rein for hours and hours at all gaits, and of course in an enclosed area. Just keep riding all the time with little contact. Western pleasure should have very little contact anyways. Just keep working at it whenever you ride... it takes time. The horse will relax and search for the contact, and its head will go lower and lower. His poll should be even with his withers. However, if this horse is an Arab, it is ok for the head to be carried a little high.... Arabs will be Arabs!