This is another 20lb bomb used by the British, except unlike other types, this one is meant to be used in the 500 lb No. 17 Mk. II Cluster Projectile. This bomb carries 3.1 pounds of TNT, slightly less than the F 20lb Mk. I bomb, which has .2 pounds more. This bomb was issued with no safety pin, so handling it made it more difficult to handle if it broke loose. It also had a parachute, the cover for which would be opened by the cluster bomb releasing it's payload.
The plugin used is Armory 3D, used to render the 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.