The ProSeal LMA is a major advance over the Classic LMA because of the following reasons: it allows ventilation at much higher airway pressures; it protects the lungs from aspiration and the stomach from gastric insufflation; it facilitates passage of a gastric tube and monitoring devices into the esophagus; it can be inserted like the Classic or Intubating LMA; it has its own built-in bite block; malposition is detected more readily; and, through use of techniques such as gum elastic bougie-guided insertion, correct positioning is almost guaranteed. The ProSeal can be considered a replacement device for the Classic LMA, but the Flexible LMA is still preferable for most intraoral procedures, and the Intubating LMA is still preferable whenever intubation is required. Limitations are that it is slightly more difficult to insert and requires more careful thought to use optimally.