Now that you have your PPL and have participated in some Club organised "Flyaways", you will have noticed that other aircraft types such as the Piper Arrow or Piper Lance are a little faster and with the Piper Lance in particular able to carry more passengers. To move into this type of aircraft you will need to obtain a Constant Speed/Retractable endorsement.
The retractable part of this endorsement obviously relates to the aircraft undercarriage which in this case is retracted for better streamlining in flight and thus better performance. The constant speed component relates to the propeller which has a variable pitch and thus provides for better power management and performance. This endorsement covers the principles in detail together with flight time as required