The Hatch Set #1 comes with two turrets both with a swiveling twin barrel gun and a machine gun and two hatches all cast from resin.

Each hatch is 0.9 inches (24mm) in diameter 0.20 inches (5mm) tall and will fit into a 0.7 inch (18mm) diameter hole.  This hatch will work on most Games Workshop Space Marine and Imperial Guard vehicles.