There are more then one band with this name.

1.
The NPK - http://myspace.com/thenpk

Hailing from the music scene of Northern California, The NPK create a potent collection of original work. Although the three musicians arrive from varied backgrounds and influences, they come together around the appreciation of quality music regardless of it's name. The NPK recently finished their first full length album. This self-titled debut was independently produced and released. The trio will play a few c.d. release parties and shows before heading back into the studio for their second album.

2.
The NPK is slovak punk-rock band.
http://www.npk.wz.cz/ Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.