I went to RS, and the guy had no idea what I was talking about. I searched their website, but not really finding anything called a Piezo Tweeter? I see them on Ebay. Maybe Radio Shack no longer sells them, hmmmm.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85