This offensive grenade is copied fromthe Polish Zaczepny wz. 33, but made of thicker sheet steel.
Also the 18mm threaded hole in the neck is larger to fit the B-3 fuze (copy of the Polish fuse wz-31).
It was manufactured by the "Industries de Guerra de Catalunya" for the Republican Army in 1938.
It is not the same grenade as the "Bola de Cama" which has smaller 15mm threads.

Length w/fuze :
Length w/o fuze :
Diameter :
Weight :
Filling :

Photo © Dani.