From the publisher's site:
With this Wings of Glory accessory, you will never run out of flight stands anymore. Included in this bag are 24 additional pegs which are used in the game to mark the altitude of your airplane.
Whatever the size of your bomber collection, the 24 pegs included in the bag will allow you to get your planes above the normal limit of 4, for use with the “Fly higher” rules, or to make up for damages or losses.
Six long pegs and 18 short pegs are included in each bag.