Dever Cheltenham Gag, Rubber covered mouthpiece.
 
This Gag is effective with some horses, acting on the poll and the corners of the mouth. The poll pressure will lower the head and encourage flexion. This rubber covered version has a warmer feel, and is softer on the horses mouth.  Needs to be used with gag cheeks, which can be purchased separately
 
Stainless Steel 

Available Sizes; 5"/12.5cm,  5.5"/14cm, 6"/15.5cm
Code 25B339R