The Bach Megatone gold mouthpieces use as their baseline the original Bach mouthpiece designs.  They differ in that they possess more than double the outside mass of the original.  The greater mass darkens the tone and permits a greater dynamic range than the original.  They are additionally equipped with a larger throat that affords less resistance and further enhances the power a player is able to muster.  They are popular among pop and jazz players, especially in environments where the horn is not being amplified in a public address system.