 The mullen provides extra space for the tongue, instead of constantly pushing into it, resulting in more tongue relief, and making it more comfortable, but the mullen does not have as high of a port as a curb, thus does not offer full tongue relief.This bit is generally considered a very mild mouthpiece, although this varies according to the type of bit leverage (snaffle, pelham or curb), and improper use may make it harsh, since the majority of the bit pressure is applied on the sensitive tongue.Materials