GBU-39 SDB (Small Diameter Bomb). Airman 1st Class Matt Aggers (left) and Staff Sgt. Randy Broome perform a final check of the stowed twin wings on four ground-training Guided Bomb Unit-39 small-diameter bombs loaded on an F-15E Strike Eagle at Royal Air Force Lakenheath, England, on Aug. 1. (U.S. Air Force photo/Master Sgt. Lance Cheung)