This is a standard German training grenade made to simulate the experience of throwing a live stick grenade. Unlike the throwing grenade, these ones were fitted with a small black powder charge and a fuse and pull cord. This one has acquired a WW1 end cap at some point in its life. The handle is marked Ub. for übung (practice) as well as 42brb indicating its manufacture in 1942 by Richard Rinker GmbH.