The 3M is a very popular choice for 3C players looking for a familiar feel but with more core in their sound and more improved articulations. All 3 Series GR Mouthpieces have the same rim and alpha angle. This provides a consistent feel between all GR 3 Series Models, allowing the feel to be the same to easily meet any musical demand.

3XS GR Trumpet Mouthpiece
• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• XS cup: with an even smaller volume than the S cup, the XS is an efficient lead size for those who are comfortable with very little room inside a mouthpiece. It produces a sizzling, brilliant sound through the entire range and is especially well-suited to the extreme high-range.

3S GR Trumpet Mouthpiece
• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• S cup: The versatile GR S cup can be used in varied musical situations. The sound is big and brilliant. Projection is excellent. The backbore is the GR #1, with good core to the sound. The S cup volume is small, though it has ample lip room for most players. This is an ideal solution to those who bottom out on conventional commercial cups. The alpha angle is not too high and does not impinge the lips; furthermore, it has the ability to lightly grip and keeps the lips held into place for great endurance. This cup is great for lead, show work, studio work, and all-around playing.

3MS GR Trumpet Mouthpiece
• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• MS cup: has a slightly lower alpha angle, greater cup volume, a slight increase in cup depth, and a larger backbore---the GR #2---than the S cup. This is a great all-around cup with a huge, brilliant sound. The added volume and a slightly lower alpha angle give the player more lip room: an ideal solution for players who find that the GR S cup is a bit tight for them. The sound is big and full with an excellent core. It has less edge than the S cup and works well in all playing situations.

3M GR Trumpet Mouthpiece
• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• M cup: has the the medium GR #2 backbore, same as the MS Cup. The M Cup has a slightly lower alpha angle, more volume and depth and greater lip room than the MS Cup, though the playing characteristics are similar. Works very well in a variety of playing situations from commercial to concert work. An ideal all-around mouthpiece with a compact core, vibrant feel, and full of overtones. This is the most popular GR cup.

3MX GR Trumpet Mouthpiece
• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• MX cup: more volume and more cup depth, lower alpha angle than the M Cup, and the large GR #3 backbore. MX is one of the more popular cups of choice for C trumpet, and is excellent on Bb as well. It is particularly well suited to students, part-time C trumpet players, and top studio musicians that want an efficient C trumpet mouthpiece. The MX cup offers more resistance than the VC or CX cups. It is popular for larger, less resistant horns and for light chamber work. The MX cup projects well; the tone is brilliant and very even throughout all registers; the upper register speaks very easily with precise intonation. Light articulation is very easy with the MX cup. If you are looking for a cup that is fat, precise, and brilliant, the MX cup is an ideal choice.

3HC* GR Trumpet Mouthpiece
The Haefner 3HC is by far most surprising of the Haefner mouthpieces. The purpose behind this design was to produce an orchestral mouthpiece that could stand up against the 1C and 1½C. The result is one of the most free-blowing 3-size mouthpieces on the market. It requires a strong player, and will work very nicely on Bb, C Eb and D. It simply makes any horn sound huge. This mouthpiece is evolved from a 70's 3c.

• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• HC* cup: a variation of the HC, designed for all-around Bb use, featuring a higher alpha angle (similar to M cup) and a larger cup volume. This design allows for added lip support and efficient playing characteristics throughout the range of the trumpet. The C* has an improved throat entrance over older, "conventional" C cup designs, which allows improved articulation, accuracy, and efficiency, along with a pure core of sound not found on most traditional mouthpieces.

3HC** GR Trumpet Mouthpiece
The Haefner 3HC is by far most surprising of the Haefner mouthpieces. The purpose behind this design was to produce an orchestral mouthpiece that could stand up against the 1C and 1½C. The result is one of the most free-blowing 3-size mouthpieces on the market. It requires a strong player, and will work very nicely on Bb, C Eb and D. It simply makes any horn sound huge. This mouthpiece is evolved from a 70's 3c.

• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• HC** cup: a more open throat entrance than the HC*, requiring more strength. It's a powerful cup that produces a great volume of sound, good articulation, and excellent projection. A good choice for the orchestra, concert band, solo work, or quintet.

3VC GR Trumpet Mouthpiece
• GR 3 Series rim: a slightly flatter feel than the GR Standard rim, it has a similar feel to Bach 3 rims, but with GR improvements in comfort and articulations. The bite is softer than the Standard GR Rim and GR E-Rim. The larger bite radius may make the rim feel larger. The outside diameter is slightly narrower than the Standard GR Rim. This is a generous rim with excellent grip and support.
• .66" rim diameter, approximately equivalent to a Bach 3
• VC cup: a special cup designed specifically for use on the C trumpet. It has the same alpha angle as the L cup. The upper and lower cup have a slightly larger radius, and a lower beta angle. This formula makes more of a V-shaped cup, but articulation and brilliance of tone are outstanding. The VC Cup was designed to project in the orchestra. The shape of the throat entrance is excellent for C trumpet. The sound is big and projects in a rich, brilliant manner; furthermore it is very easy to shade and color. The upper register is efficient and strong while the lower is warm and rich. The throat entrance, throat, bore, and backbore are a little more open than the standard MX, L, and LX. This cup can be played on Bb with good results, though it requires a very strong player. Many players use the 66L or 67L on Bb trumpet and the 66VC or 67VC on C trumpet. The VC cup is an excellent choice for symphonic applications and use in other large ensembles. It offers the serious C trumpet player a huge symphonic sound that really projects.