Mercedes W639 Front Seat Left N/S Head Rest Restraint Leather A6399700300

Mercedes W639 Front Seat Left N/S Head Rest Restraint Leather is an original interior trim component designed for installation on the left-hand passenger seat. Thanks to its factory design and precise fit to the backrest geometry, it provides proper head support and a consistent cabin appearance with the rest of the leather upholstery.

Specifications and technical data

• SKU: rhd-A6399700300
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6399700300
• Substitutable numbers: A6399700300, A 639 970 03 00
• Location on the vehicle: Front, Left
• Upholstery material: Leather
• Category: Headrests

Purpose and compatibility

The presented headrest has been designed specifically for the Mercedes W639 model family, intended for installation on the front left seat. The mounting structure is adapted to the standard backrest guides, which allows for effortless height adjustment and stable seating of the component within the seat structure.

Its original Mercedes origin guarantees the maintenance of proper geometry, appropriate core rigidity, and compatibility with the standard seat line, without the need for modifications or adaptations.

Construction and upholstery material

The headrest belongs to the Headrests category and is finished with leather upholstery, matched to Mercedes interior finishing standards. The leather ensures easy maintenance, resistance to typical operational wear, and visual consistency with other seat elements.

The headrest core has been designed to evenly distribute pressure on the head and neck while maintaining appropriate vertical axis rigidity. As a result, the component serves both a comfort and protective function in daily vehicle operation.

Ergonomic function and safety

A properly selected headrest in a Mercedes W639 is crucial for the ergonomics of the driving and passenger position. The presented component:

• enables height adjustment within the range provided by the seat manufacturer,
• stabilizes the cervical spine during driving,
• supports the operation of passive safety systems through proper head positioning relative to the backrest.

Thanks to the use of leather upholstery, the headrest works well with the backrest profiling, limiting head movement and ensuring consistent support on longer journeys.

Condition, application, and benefits of replacement

The component comes from the secondary market, making it a cost-effective solution for replacing a damaged or missing headrest in the vehicle. Choosing an original leather headrest allows you to maintain the visual consistency of the interior, avoid differences in material shade, and ensure proper fitment with the seat guides.

In practice, replacing the headrest with an original component:

• restores full functionality of the head support adjustment,
• eliminates play or instability resulting from non-matching replacements,
• maintains the vehicle's value by preserving factory interior specifications.

Expanding your Mercedes interior equipment

If you are planning a comprehensive repair or upgrade of the seating area in your Mercedes and need other elements from the same group, such as additional headrests, adjustment elements, or supplementary seat components, check the available parts in the Mercedes Headrests category.

For users interested in a broader look at the operation of diesel-engined cars and the costs of secondary market parts, a comparative article on BMW units may be helpful – you can find it here: BMW N47 vs M57 / M57N / M57N2 – ranking of legendary diesels.