Abbey Hard Rubber Non Flexible Mullen Hanging Cheek Hard Rubber Mullen Hanging Cheek £81.95 imperial size: [Choose]5"51/4" Quantity: at £81.95 each Add To Basket A rubber coated Mullen Hanging Cheek. For horses that require a little poll pressure for their flat work. A non flexible mouthpiece. A thinner style is available from Beris. 51/2" is out of stock with suppliers. On order. Around 3 weeks.