3.7b E-Bow

An EBow (electronic/electromagnetic bow) is a small, hand-held magnetic device
that causes guitar strings to vibrate continuously, resulting in a long, 
sustained tone, similar to a violin bow. The band has used EBows in many
studio recordings in all eras.

EBows have been used live on songs like Shame and Porcelina, and is featured
prominently on Sinfony from Vieuphoria, and in the solo from There it Goes.
For more information, check EBow.com.