Trust Inno Sense Hard Mullen 3 ring non flexible 3 ring gag from Trust £89.95 metric size: [Choose]13.5 Quantity: at £89.95 each Add To Basket 0 in your basket View Basket Checkout A smooth non 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.