It is very rare to see a TBU apple for sale. We ahve a huge parts excahnge at Danville but apples are a rarity. The bases are sold separately as are the emitters and the holders. I have not seen Tamiya sell apples separately. Bases are about $30 at a AAF Tank Museum and the IR emitter about $10(?). Most guys keep one or two for spares. FYI....Impact apples and bases are NOT intrecangable with Tamiya. They look exactly the same but are of different proportions. The apple and base MUST match. The IR emitters are interchangable however.