A genuine, but inert, drill Mk.II M228 "Pineapple" grenade complete with release pin. Used for practice drill.
The pineapple design was first adopted during WWI and has been seen on all sides. Contrary to popular belief the segments of the pineapple are actually for grip rather than for fragmentation effect. This type of grenade is probably one of the most recognisable hand grenades in the world due to its presence in various US films and productions, e.g. Band of Brothers, etc. This specific grenade is still used in training, essentially due it being universally recognised as a grenade.
This grenade is unpainted. Various colours have been used in the past and in fact the majority of WW2 era grenades were painted yellow. The standard for an MKII is green with a yellow rim near the fuse. Despite being used in training it was phased out of active service during the Korean wars and saw its final days in Vietnam. However, many nations continue to use them to this day.