Body
The No. 36 Grenade, also known as the Mills Bomb. This was the standard hand grenade that was used by the British Army during WW1 and through WW2, also issued to the Home Guard, Auxiliary Units, and the SOE.
It could be fitted with a 4 second fuze for hand throwing, or a 7 second fuze for firing from a cup discharger, that was fitted on the end of a Lee Enfield SMLE rifle, and this allowed the grenade to be thrown a longer distance. When it was fired from a cup discharger, it required a round metal plate to be screwed on to its base, called a gas check plate.
The sectioned image is an inert grenade, with an inert 4 second detonator fitted for training and display.