(The following is taken from their home page) Standard Sound Sleeve is best for all-around work, balanced to give the right amount of slot-lock and sound centering qualities. Sound Sleeve “Y” model fits slightly higher up on the shank to accommodate the longer Yamaha andBenge trumpet receivers. Lead Sleeve is designed for upper-register playing, where you want a maximum amount of control without hindering high notes. It weighs nearly as much as the standard Sound Sleeve, but since it’s mass is distributed over a greater length, it’s effects are more subtle. MEGASLEEVE is designed for players that want to add that Heavy-weight…