Fishman Neo-Buster Humbucking Soundhole Pickup &amp; Feedback Buster<div style="text-align: left;"><strong>[Product Information]</strong><ul><li><span class="a-list-item"> Neodymium humbucking magnet structure for warm humbucking tone and exceptional string balanceIntegrated feedback-buster for high-volume playingLow profile， high impedance design needs no batteryFlexible surround reduces howling in high volume situationsEasy installation with no alteration fits most standard acoustic guitars with 3-7/8 or 4 diameter soundholeTool-free installation </span></li><li><span class="a-list-item">  This humbucking magnetic soundhole pickup produces a warm and full sound while also greatly reducing hum and unwanted interference </span></li><li><span class="a-list-item"> It also shares the same neodymium magnet structure as the award-winning Rare Earth pickup for exceptional string balance and incredible acoustic clarity </span></li><li><span class="a-list-item"> Its low-profile， high impedance design needs no battery </span></li><li><span class="a-list-item">  When you need to play in high-volume situations， the integrated soundhole cover reduces the build-up of energy inside the guitar that often leads to uncontrollable howling </span></li></ul></div><img src="http://ecx.images-amazon.com/images/I/41mNhefEuBL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51LZ-oSMB9L.jpg" noproxy>