Check the listing for details. Bartolini HR-4.5AP Pre-Wired 2 Band EQ Active/Passive Preamp. Condition: New. Listed at 179.00 USD. Bartolini HR-4.5AP Pre-Wired 2 Band EQ Active/Passive Vol, blend, individual bass & treble The Bartolini HR-4.5AP Pre-Wired 2 Band EQ Active/Passive Vol, blend, individual bass & treble. FREE shipping anywhere in the USA! A Pre-Wired harness saves the time and aggravation of wiring your pre-amp and pots into your instrument. They feature our industry leading pre-amps and premium audio-quality potentiometers with smooth control and ready for years of rugged use. The HR-4.5AP/918 uses a 2-band EQ and pre-amp. Two holes for Volume control: Volume (with Active/Passive push-pull switch) – Blend. Two holes for Tone control: Treble – Bass. 2-Band Preamp: NTBT-918 Additional Information Eq 2-band Volume Controls Volume (with Active/Passive push-pull switch) – Blend Tone Controls Treble – Bass Accessories Includes: 2nd battery clip (18V option), wiring instructions