Fishman PRO-NEO-D01 Neo-D Magnetic Soundhole Single Coil Pickup w/Bonus Lulu Picks (x3) 605609105790 Neodymium magnet structure for exceptional string balance and sparkling acoustic clarity Low profile, high-impedance design needs no battery Easy installation with no alteration, plug and play right out of the box Excellent string-to-string balance and acoustic clarity Fits in soundholes as small as 3-7/8? (98.5 mm) diameter