RI,
If your asking if this can be set up to be operated by your current horn switch, the answer is yes. But it is an elaborate set up. For around 10% of that price, you can get airhorns from Hella, Fiamm, etc which have small high speed compressors, multiple horns and get more attention than the ones you are contemplating. I had 5 differently sized (different frequency) small horns and 2 compressors in my Tahoe. I routed the tubing so that both compressors fed all 5 horns. Lets just say no one ignored my horn.
http://www.autobarn.net/noname6.html
http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&productId=357181&R=357 181
http://www.duettomotors.com/miata/horns.htm
t~