Micro Piezo sticker.
Replace the sticker by the Patafix for removable attachment.
Recovery of acoustic stringed instruments: harp, bouzouki, oud, guitar ...
So DI preamp output without active imperative!
I have three in my case micros "weird" to troubleshoot when arriving on scene a flock of strange instruments (harps, for example).
It is effective as a solution on stage when static cling to a harp ... or that (the) musician always moving and hits the microphone when it does not fall.
+: Very low price: 11 euros.
-: Medium Tone (Basic piezo), but it helps out well.