Trust Bendy White Mullen Three Ring Trust White Flexible Mullen Three Ring £74.95 metric size: [Choose]14.513.5 Quantity: at £74.95 each Add To Basket A smooth flexible mouthpiece three ring gag from Trust Equestrian. Comes with neat bit rubbers. Available in metric sizes only. 12.5 to order. We are finding that the bits which are supplied with rubber bit guards sometimes get a small amount of brown staining on them. This appears to be a reaction of the rubber.