Linear Fluorescent Tube Ledvance L T5 21W 840 G5 - Cool White (4000K)

Ledvance L T5 21W/840 G5 is a linear fluorescent tube designed to deliver neutral/cool white illumination at approximately 4000K. The tube uses a G5 base and a 21-watt nominal power rating, providing even light distribution for general interior lighting applications. It is compatible with fixtures that accept T5 G5 lamps and is suitable for replacing similar fluorescent tubes in offices, retail spaces and residential rooms where neutral white light is preferred.

Advantages

The lamp offers stable, flicker-free light output when used with compatible ballasts, producing consistent colour rendering and uniform brightness across the length of the tube. Its straight T5 form factor is space-efficient and fits many compact luminaires. The neutral 4000K colour temperature balances cool and warm tones, making it appropriate for work and leisure environments that require clear, natural-looking light.

Suitable for

• General office lighting
• Retail and display illumination
• Corridors, stairwells and utility areas
• Workshops and task lighting where neutral white is preferred
• Retrofit replacement in fixtures designed for T5 G5 tubes

Key specifications

• Lamp type: Linear fluorescent T5
• Power: 21 W nominal
• Base: G5 two-pin
• Colour temperature: 4000 K (neutral / cool white)
• Colour rendering: suitable for standard interior tasks (typical CRI for this class)
• Form factor: straight tubular design for compact luminaires
• Typical applications: general-purpose indoor lighting

How to use

Install the tube into a compatible luminaire with a G5 socket, ensuring the fixture is switched off and isolated from mains power before handling. If the existing luminaire uses an external ballast, verify compatibility with fluorescent T5 tubes and follow the ballast manufacturer's instructions. After fitting, restore power and check for correct ignition and stable operation. For retrofit replacements, confirm length and holder spacing match the replacement tube.

Recommendations

Use this lamp indoors in dry locations and avoid exposure to moisture or mechanical stress. Replace tubes in matching pairs where even light output is required across multiple fixtures. Dispose of used fluorescent tubes according to local regulations for lamps containing small quantities of mercury and other components.