Cheap And Discounts 10pcs Piezo Elements Buzzer Sounder Sensor Trigger Drum Disc Copper Piezo Speaker 12MM 20MM 27MM 35MM 50MM Piezoelectric Wholesale. Buy Directly From Merchant WZXHFL Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.