This is a listing for a smooth taper filter. It uses high-precision metal film resistors. While similar to Human Gear products, it is an original design. This filter is suitable for 500kΩ volume pots, which are commonly used with humbucker pickups. It is also suitable for guitars with pickups other than humbuckers, as long as the volume pot is 500kΩ. Attach it by soldering to terminals 2 and 3 of the volume pot. If you wish to purchase multiple units, please leave a comment and I will create a dedicated page for you.