DZS Elec 15PCS 35mm Piezo Disc Transducer Contact Microphone Trigger Sound Sensor with 4 Inches Wires for Acoustic Instrument

Used these as a contact microphone and they work about as well as expected. The disc is larger than most but the wires are really thin and flimsy

i love that these are available in mass quantities for cheap, made many mics and they work great if u get good adhesion

Used as pick-ups for an art sound project. The wires are pretty thin and I brove a few of them off on accident. To be fair, I was a littke rough on them. We were recording sounds and other vibrations in many different areas. It was NOT a defect. You get a good value. The product is an OK quality. 4 stars because they worked well and I did not find any defective items as I sometimes do with these inexpensive bulk buys.

Nice size. Makes great triggers

I needed 3 to make some rock band cymbals. Can't beat the price. I am not great at soldering so having extra was useful.

Fixed the roland octopad with these. Perfect good price

We used these in a science fair project to charge a small battery from energy created while walking around. They worked great for prototyping (and demonstrating the limitations of the idea). Very easy to burn through if you need to solder them into a circuit, but not likely what most people will use them for, and with a steady hand it’s not really an issue (our 7 year old is still very new to this and killed a couple, but that’s not the fault of the product).

Really fun product, I used these to make a ton of stuff from drums to reverbs, to changing an autistic guitar into a semi electric, an making old soup cans microphones. The downside is I did get some duds that just don't work but only a couple. For the price I'm not concerned