I think this is Russian maybe WWI. Made of brass with a white metal timing ring. the ring is rated from 1-12 with 4 spaces between each number. The hole in the bit sticking out of the top is not threaded. My first thoughts was that there is a cap which fits over that and is held in with a screw. There are no marks on the fuze except the 1-12 with divisions. Hight from the flat part of the base to top of fuze 46.92mm. Dia at the bottom of the base 59.50mm. Thanks again....Paul.