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. The Fishman Neo-D humbucking Acoustic Pickup features a passive design that fits into the soundhole of most steel-string flat-top acoustic guitars. Fishman uses a state-of-the-art magnetic field/coil structure on the Neo-D (similar to their acclaimed Rare Earth pickup), and its string balance is excellent, thanks to the unique arrangement of its neodymium magnets. Installation is a snap, and this reliable pickup sounds simply fantastic live.

General Tools #582 Magnetic Pickup/Light. GENERAL TOOLS MFG. Telescoping Magnetic Pickup With LED Light, Soft Foam Grip For Ergonomic Handling, Bright LED Light, Includes: 2 LB Pickup Neodymium Magnet, Handle Extends To 28-3/4" For Hard To Reach & See Areas, Pivoting Light & Magnet Head. Want parts to build your own gaussmeter? Here is an AC magnetic field probe. It generates an AC voltage when exposed to AC magnetic fields. The greater the magnetic field, the higher the voltage generated (at 60 Hz, it produces about 1 mV per 20 mG). It can be connected to a DMM, analog voltmeter, oscilloscope, audio amplifier (see below), or recording device. Connect 3 of them in series and create a 3-axis unit. It is quite small: only 0.7" long x 0.7" diameter, with a removable rubber suction cup attached. Has 36" lead and 1/8" (3.5 mm) mono plug.