German Stick hand grenade,WW I. It is marked Carl Spaeter 5-1/2 Sek. (i.e. maker name and 5-1/2 seconds fuze) restored and INERT. Noted by Colin Stevens as "Model M15, concussion". The stick grenade was made of a pressed steel body, with a pull-friction fuze "brennzunder 24". This grenade consist of a thin iron or steel casing, or head, containing the explosive filler, which is screwed onto a hollow wooden handle, through the center of which runs a double length of cord. This cord is attached at one end to a lead ball which is part of the igniter, and at the other end to a porcelain ball. Early models have a carrying loop spot-welded to the body. The detonator had to be inserted by the user. 2 types of frag sleeves could be used, prefragmented and smooth. Operation: The metal cap is unscrewed from the handle and the porcelain ball is pulled.This will pull a wire through the delay pellet. The grenade is then thrown and after 4-5sec. delay the delay pellet will initiate the detonator.