Qref Media is the fastest growing publisher of Quick Reference books and tools for avionics, aircraft, marine systems, and personal GPS. Get the most out of the avionics, aircraft, GPS or marine system you use. Qref quick reference books and cards are one-of-a-kind checklists that have become the standard reference for GPS and avionics systems. Qref aircraft checklists are, quite simply, the most reliable checklists available. Why? More hours are spent in developing a Qref checklist than any competitive produc, and our authors have more experience and expertise. To prove this, Qref checklists have been accepted as FAA/Industry Training Standard (FITS) supporting materials, which means they were found to be more convenient, more accessible, and more relevant to today's pilots. Qref checklists are the only checklists to achieve this FAA endorsement.