This is the Mark I GP 250 lb bomb used by the Britain on multiple types of aircraft, from bombers to fighters, such as the Wellington or Typhoon. There are 6 different versions of the GP 250lb. It weighs 247 pounds, with an explosive mass of 68 pounds of T.N.T. or 63 pounds of Amatol 80/20. It has a diameter of 10.3 inches, and a total length of 54.2 inches. A bomb with a time delay fuse has red fins, and this model comes with textures for bombs with or without a time delay fuse.
The plugin used is Armory 3D, used to render the PBR images you see. The information in the description can be found in British Explosive Ordnance, published by Navy Department Bureau of Ordnance on June 10, 1946.