Apollo 11 carried five personal preference kits.
Personal preference kits, or PPKs, were small bags that let astronauts take personally meaningful mementos within strict spacecraft weight limits. Each Apollo 11 kit weighed about 0.5 pound (0.23 kilograms), making the total allowance surprisingly modest.
Three kits—one for Neil Armstrong, Buzz Aldrin, and Michael Collins—were stowed aboard the command module Columbia. Two additional kits were carried in the lunar module Eagle. This arrangement explains why the total was five rather than simply one kit per astronaut.
The contents could connect the mission to history. Armstrong’s lunar-module kit included pieces of fabric and wood from the Wright brothers’ 1903 Wright Flyer, along with an astronaut pin associated with the Apollo 1 crew. PPKs should not be confused with the mission’s scientific samples, cameras, or standard equipment: they were personal keepsakes and commemorative items.