Amazon.com: Parts Express SPST NO Momentary 22mm Stainless Steel Waterproof Touch Piezo Tamper Proof Switch with Red Ring 3-24 VDC : Industrial & Scientific
Amazon.com: 50MM Guitar Pickup Piezo Transducer Prewired Amplifier With 6.35MM Output Jack for Acoustic Guitar Ukulele Cigar Box Guitar : Musical Instruments
Amazon.com: 3-pack 27mm Piezoelectric Disk Elements (Contact Pickups) with 2" Leads : Musical Instruments
Piezoelectric Sensor, LDTM-028K, Silver Ink Electrode, No Mass Version: Amazon.com: Industrial & Scientific
Amazon.com: Goedrum Pack of 5 Prewired 35mm Piezo Disc and Double Sided Adhesive Foam Circle : Musical Instruments