12pc. 20mm Piezoelectric Buzzer Contact Mics with Leads - Use for Cigar Box Guitar Pickups, Drum Triggers & More Great for Acoustic Guitar Pickups, drum triggers, Contact Pickups & more! 20mm outside diameter with pre-soldered 2-inch leads High-quality Murata-brand product - don't be fooled by cheap knock-offs Great for Cigar Box Guitars, Acoustic Guitars, Ukuleles, Dulcimers, Banjos & more Can also be used as buzzers and alarms