250K SDP-250 Potentiometer, For Volume/Tone, SD Logo, Ultra Soft Action. Tailored by Bourns to exact Seymour Duncan specifications, the 250k and 500K soft-turning Seymour Duncan potentiometers feature high quality construction, tapered control, and a feel that's right - all with a name you trust. Use it as a volume potentiometer or tone control. You can feel the difference. Come with the mounting hardware.