Either name that is commonly given to this type of multi-ring bit is quite a misnomer, since it is neither a gag, nor does it elevate. This bit is essentially the same as the two- and three-ring bits, except that it uses shanks to accentuate the length between the upper and lower rings. There is also an attachment in the snaffle position, but it is usually a piece welded onto the shank, so in effect it is more like a D ring or full-cheek snaffle in this respect. The upper ring attaches to the cheek pieces of the bridle, and when there are reins attached to the lower rings, the action is similar to a curb without a curb chain.
The leverage action that occurs when the lower rings are used puts a great deal of pressure on the cheek pieces of the bridle, which in turn pull down on the poll. Hence the effect of this bit is to lower the head, not raise it as is implied by “elevator” or gag (a true gag is for raising the head).