Nathe Mullen Ported Loose Ring - Hard density - 15mm 15mm thickness hard density £66.95 This bit is currently out of stock please contact us for more details. New thinner style of the ported Nathe loose ring for 2020. New thinner style of a synthetic ported mouthpiece. - 15mm thickness Hard density. Port is slightly forward facing. As with all synthetic bits please keep an eye out for excessive chewing on the mouthpiece and discontinue use if this happens.