New Old Stock Russian (NOS) Russian Military Surplus K40Y-9 Paper in Oil (PIO) capacitor - .015uF 400V. The K40Y-9 are high quality PIO capacitors made for Russian military. The conductor is made of aluminum foil and the dielectric is oil saturated paper. Similar construction to a Sprague Vitamin Q. Caps are hermetically sealed in a metal case with glass sealed ends. These capacitors provide excellent sonic characteristics, and a high tolerance within a wide temperature range. These capacitors are ideal for the neck position Humbucker. Use the .015 in the neck pickup and pair with a .022 in the bridge pickup in a Les Paul, and you've got the combination that Clapton usedin his SG that made the "woman tone" vibe he was famous for during his Cream days. Great way to improve the tone of your guitar, or for use in other audio applications.