Trumpet mouthpieces have many parts that give a variety of results, which are explained on this page. If you are a beginner or intermediate player, it’s best to use a standard mouthpiece unless you truly have a need for a specific configuration. Your teacher would be the best person to advice you on this. You will notice that when you alter a part of your mouthpiece it always comes with a price. Probably the most important aspect of choosing a mouthpiece is remembering that a mouthpiece will not make you sound better, give you more range or drastically improve your playing. Improvement only comes from correct and consistent practice.