The Splitterring was a fragmentation sleeve for the M24 and M43 stick grenades, developed by the Wehrmacht Heer in 1942. The term is a German compound word combining Splitter (splinter or fragment) and Ring (ring). As German stick grenades had only a thin steel casing surrounding the explosive charge, they relied principally on blast for effect (making it an "offensive", rather than "defensive" grenade, the latter relying on fragmentation and thus creating a casualty radius higher than the throwing distance). The addition of a Splitterring to a standard stick grenade gave it greatly increased fragmentation ability. Offensive grenades are best used in enclosed spaces such as buildings or bunkers; fragmentation types are also much more effective against personnel in the open. The availability of the Splitterring allowed the stick grenade to be quickly and simply modified by the user, so it could be used in either role. Other nations often produced separate types of offensive and defensive grenades.