In addition to their full kits, Admiralty Model Works offers a number of accessory sets to jazz up 1/700 scale projects, among them this set of "universal" naval mines.

I was working on Tamiya's Hirashima class minelayer which had pretty decent mines molded to the deck, but when these little beauties arrived in the mail I abandoned all thought of using the kit parts. Cast as 24 individual parts on a thin resin wafer, the spherical mines atop their square bases each total about 2mm in height. Small as they are, they are very cleanly cast with discernable spines on the spheres as well as miniscule but sharply molded details on the bases. They should look great once painted and installed. There is even a photo and a couple of line drawings on the back of the package for reference, and at US $6.00 for a set of 24 (25 cents each!) they are an affordable way to upgrade your little minelayers.