The "Butterfly Bomb" or SD2 was a small weapon of about 2Kg in weight which were packed in a container holding 23 in total which resembled a 50Kg bomb. When dropped, the container split open spilling its contents of butterfly bombs. The bombs, when packed had an outer thin metal cover the same shape as the bomb which hinged in two halves and opened after a short delay to reveal vanes which rotated as it descended to remove an arming spindle to arm the fuze.
The bomb could be fitted with a number of different fuzes, i.e. No 41, No 67, No 70B. The 41 fuze was designed to explode on impact. The 67 was a delayed action and very dangerous fuze as there was no way to tell if the bomb would explode immediately it was moved or whether it was ticking or not. the 70B was just as evil because it was designed to be a booby trap and explode immediately the bomb was moved
