Practice mortar 81mm, this item is NOT LIVE. It is inert, harmless, an ornament only. This will not explode, but it will collect dust in a man cave somewhere. There is no detonator, and no explosive either. Cavity has been filled with grout, you are able to see by unscrewing the blank cap where a detonator would originally have been fitted. It is very heavy for its size because of the grout filling, unsure of courier cost but will take a guess. Stamped on the body is what I guess is a manufacturing date of 6/42. Painted in white is 'PRAC MK3'.