The G10Q T9 Circline 20W 850 5000K Circular Fluorescent Tube is a compact circular replacement lamp designed for compatible fittings requiring a 20W G10q 4-pin Circline fluorescent lamp.

Producing a crisp 5000K Neutral Daylight (850) light, this circular fluorescent tube provides bright, broad and even illumination from its compact ring-shaped design.

With an approximate 160mm outside diameter, this is a particularly compact Circline lamp suitable for compatible ceiling lights, task-lighting fixtures and specialist circular fluorescent fittings where physical size and connector configuration are important.

This lamp is particularly useful for replacing older or difficult-to-find 20W 850 G10q circular fluorescent tubes. When replacing an existing Circline lamp, always match the wattage, G10q base, colour code and physical diameter rather than relying only on the circular appearance.

Key Features

• 20W circular fluorescent lamp
• T9 Circline design
• G10q 4-pin base
• 850 colour code
• 5000K Neutral Daylight
• Approx. 160mm outside diameter
• Compact circular / ring-shaped design
• Bright, clear light appearance
• Broad and even light distribution
• Suitable for compatible G10q Circline fittings
• Ideal replacement for compatible 20W/850 G10q circular lamps
• Hard-to-find fluorescent replacement lamp
• Suitable for residential, commercial and specialist applications

Technical Specifications

Compatible & Replacement References

This 20W 850 G10q Circline fluorescent lamp may be suitable as a replacement where the existing lamp requires the same:

20W • G10q • 4-Pin • 850 • 5000K • Approx. 160mm

Useful replacement and identification searches include:

Important Compatibility Information

Circular fluorescent lamps can look very similar while having different wattages, bases, diameters and colour temperatures.

For this NZ Lights product, check:

✓ 20W

✓ T9 Circline

✓ G10q

✓ 4-Pin

✓ 850

✓ 5000K

✓ Approx. 160mm outside diameter

Do not select a replacement simply because another fluorescent tube is circular or has a similar diameter.

The G10q connector, wattage and physical dimensions should all match the requirements of your fitting.

How to Identify the Correct Replacement

Before ordering, check the markings printed on your existing circular fluorescent lamp.

For this product, look for:

20W + G10q + 850 + 5000K

You may also find markings such as:

20W/850

FC20W/850

G10q

850

5000K

or another manufacturer-specific model number.

Also measure the outside diameter of the existing circular tube.

For this product:

Outside Diameter: Approx. 160mm

Matching the physical diameter is particularly important with smaller Circline lamps.

What Does 850 Mean?

The 850 colour code identifies the colour characteristics of the fluorescent lamp.

8 = CRI approximately 80+

50 = approximately 5000K colour temperature

Therefore:

850 = CRI 80+ / 5000K Neutral Daylight

This is particularly useful when identifying an older fluorescent lamp because 850 may be printed on the tube without “5000K” appearing separately.

If your existing lamp says 20W/850, it indicates a 20W fluorescent lamp with approximately 5000K light.

You should still confirm the G10q base and physical dimensions before ordering.

G10q 4-Pin Base – Important Compatibility Information

This product uses a G10q 4-pin base.

Please check the connector on your existing circular fluorescent tube carefully before ordering.

For this product, match:

20W • G10q • 4-Pin • 850 • 5000K • Approx. 160mm

Do not choose a replacement based only on wattage or circular shape.

850 / 5000K Neutral Daylight

The 850 / 5000K Neutral Daylight colour produces a crisp, bright light appearance.

It is cooler and whiter than traditional Warm White lamps while being slightly softer than typical 6500K Daylight fluorescent lighting.

This colour is particularly suitable for:

• Kitchens
• Bathrooms
• Utility areas
• Work areas
• Offices
• Task lighting
• Commercial interiors
• Retail spaces
• General-purpose ceiling lighting
• Areas where clear, bright illumination is preferred

If maintaining the same light colour as your existing installation is important, check whether 850 or 5000K appears on your old lamp.

Compact 160mm Circline Lamp

With an approximate 160mm outside diameter, this is a relatively compact circular fluorescent lamp.

The smaller diameter makes correct measurement particularly important, as larger Circline tubes may have the same general appearance but will not physically fit the same fixture.

Before ordering, measure straight across your existing circular lamp from the outside edge of the tube on one side to the outside edge on the opposite side.

For this product:

Outside Diameter: Approx. 160mm

Also check the G10q 4-pin connector.

Hard-to-Find 20W Circline Replacement

Traditional circular fluorescent lamps are becoming increasingly difficult to source as older fluorescent ranges are phased out.

If your existing fitting remains operational, replacing the lamp with the correct 20W G10q Circline fluorescent tube may allow you to continue using the existing fixture without replacing the complete light fitting.

Keep your old lamp until you have confirmed the replacement and compare the wattage, base, colour code and diameter carefully.

Common Applications

The 20W G10q 850 Circline fluorescent lamp is suitable for compatible:

• Compact circular ceiling fittings
• Residential lighting
• Kitchens
• Bathrooms
• Hallways
• Utility areas
• Task-lighting fixtures
• Commercial interiors
• Retail environments
• Specialist circular fluorescent fittings

The circular design distributes light around the complete ring, providing broad illumination from a compact fluorescent source.

Need Help Finding the Correct Circline Lamp?

If you're unsure whether this 20W G10q 850 5000K Circline lamp is the correct replacement, send NZ Lights a clear photo of your existing lamp showing the printed markings and connector/base.

If possible, also provide the outside diameter of the existing circular tube.

We can help identify the correct wattage, base, colour code, colour temperature and physical size required for your fitting.

Why Buy from NZ Lights?

NZ Lights specialises in replacement lamps and hard-to-find lighting products for residential, commercial and professional applications throughout New Zealand.

• Specialist replacement lighting range
• Hard-to-find Circline fluorescent lamps
• G10q circular lamps available
• Compact and specialist Circline sizes
• Multiple wattages and colour temperatures
• Single and bulk quantities available
• NZ-based product support
• Fast nationwide delivery
• Daily dispatch from Christchurch, New Zealand