This listing is for a Pair of 5Z4G UK made rectifiers.  Similar to 5Y3 and also substitutes for GZ32 in some amps including Quad II.  Military Surplus stock, never used or even opened before.   3 pair available.   The price is realistic, no offers please.  Shipping A$39 international and A$14 within Australia.  You pay No additional shipping if you buy more than one set.