KLOS J/4 Jazz 4 String 20 Fret Carbon Fiber Neck

The KLŌS Carbon Fiber Bass Neck J4 is a modern upgrade for players seeking maximum stability, consistency, and performance from a traditional J-style 4-string bass. Constructed from advanced carbon fiber, this neck resists warping, temperature shifts, and humidity changes—keeping your instrument in tune and feeling the same night after night.

With its lightweight design and smooth, fast-playing feel, the J4 neck enhances balance, sustain, and overall responsiveness without sacrificing familiar ergonomics. Ideal for touring musicians, studio players, and anyone looking to modernize a classic bass, the KLŌS J4 carbon fiber neck delivers reliable performance with minimal maintenance and a clean, contemporary aesthetic.

Neck Type: Jazz

Strings: 4

Scale Length: 34"

Color: Black

Fret Materia: lStainless Steel

Fret Size: Medium Jumbo

Headstock Shape: KLOS F-Series

Machine Heads: KLŌS Regular

Truss Rod: Standard

Truss Rod Nut: 4 mm Hex

Number of Frets: 20

Neck Material: Carbon Fiber Composite

Nut Material: Graphtech Nu-Bone

Fingerboard Material: Composite Ebony

Finish: Epoxy

Inlays: White Dot

Nut Width: 38 mm

Neck Width at 1st Fret: 20.25 mm

Neck Width at 12th Fret: 21.85 mm

Fingerboard Radius: 11"

Headstock Shape: 3+1

Neck Pocket: Width: 2 1/2” (63.45 mm)

Length: 3.875” (98.4 mm)

Depth: 5/8” (16 mm)