No. 7, elec-electronic, c/o 1 ea base, adapter, nylon, molded, 2.0 in. Diameter x 0.62 in. Lg, w/1 ea bracket, holder, copper, chromiumplated on one end and 2 ea contact, brass, silver plated and 4 eaplug, banana, brass, nickel plated on the other. For test set, underwater mine, mk 303 mod 0, model no.