This is a really SPECIAL bass. Vigier basses are among the most comfortable in the market, and have unique necks with no truss rod in them. Instead, there's a carbon fiber strip that runs along the neck adding stability and removing the dreaded ghost notes that are present in so many basses (according to Vigier, this has a lot to do with the use of standard truss rods). The result is a bass with a full bodied sound and no dead notes anywhere. Patrice Vigier believes that if the neck and fingerboard are perfectly shaped like on a good double bass, there's no need for a truss rod; the factory set up is so good that it just plays like a dream. As you can see, this is the Delta fretless version of the Passion IV Bass, meaning it has a special metal fingerboard. This material produces an endless sustain and a feel like no other. the new pickups and electronics allow you to go from an extremely bright (but nice) sound to an almost old school fretless sound just by using the Treble pot. Amazing! Vibratos respond better than on most fretless, and notes ring with a vocal-like quality. Harmonics just jump out of this bass, and techniques such as tapping and slapping (yes, on a fretless bass) sound awesome. But if you prefer a more traditional full bodied sound, this bass also delivers that easily. Of course, the metal fingerboard will give you years of use with no wear from the strings.