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FREE DELIVERY FOR ORDERS OVER €150 IN FINLAND / ORDERS BEFORE 2 PM WE TRY TO SHIP THE SAME DAY
FREE DELIVERY FOR ORDERS OVER €150 IN FINLAND / ORDERS BEFORE 2 PM WE TRY TO SHIP ON THE DAY
Osram Decostar 51S MR16 halogen lamp 12V 20W 36° GU5.3 2900K – 46x51mm
Osram Decostar 51S MR16 halogen lamp 12V 20W 36° GU5.3 2900K – 46x51mm
Osram Decostar 51S MR16 halogen lamp 12V 20W 36° GU5.3 2900K – 46x51mm

Osram Decostar 51S MR16 halogen lamp 12V 20W 36° GU5.3 2900K – 46x51mm

SKU 4050300272634
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€8.70 - €8.70
€8.70
€8.70 - €8.70
€8.70

includes VAT 25.5% Shipping costs are calculated at checkout.

Availability:
Out of stock

The Osram Decostar 51S is a classic MR16 halogen lamp that replaces broken MR16 halogens in light fixtures. 12 V halogen technology, 20 W power, and a 36° spotlight beam angle — suitable for older MR16 fixtures where an LED alternative does not work (e.g., due to compatibility issues with a transformer or dimmer). The 2900 K color temperature produces a warm and natural halogen tone. UV protection shields the illuminated object from harmful radiation.

12 V halogen — requires a 12V transformer. GU5.3 base (MR16). UV-protected. The service life of 4000 h is typical for a halogen.

⚠ Order item

Delivery time approximately 2 weeks from the order. Availability can be checked in the shopping cart.

Technical specifications

  • Product type: halogen lamp, MR16
  • Brand: Osram
  • Series: Decostar 51S
  • Lamp type: MR16 (Multifaceted Reflector, 16/8 inches = 51 mm)
  • Base: GU5.3
  • Power: 20 W
  • Beam angle: 36°
  • Color temperature: 2900 K (warm white)
  • Color: colorless (clear light)
  • Nominal voltage: 12 V
  • UV protection: yes
  • Low-pressure technology: yes
  • Infrared coating: no
  • Dimensions: Ø 51 × 46 mm
  • Service life: 4000 hours
  • Product code (EAN): 4050300272634
Compatibility and installation

UV protection — an important feature

The Decostar 51S includes a UV-protected bulb that prevents harmful ultraviolet radiation from reaching the illuminated object. This is especially important for:

  • Lighting artwork: UV radiation fades paints and fabrics
  • Retail lighting: UV radiation can damage textiles and other products
  • Food lighting: in pickup points and displays, UV can degrade food quality

UV protection is one of the most important differences between halogen and LED alternatives — LED lamps generally do not produce significant UV radiation, but a high-quality halogen needs specific UV protection, and the Decostar 51S includes it as standard.

Why stick with halogen?

MR16 LED alternatives are available, but compatibility issues are common — especially with older halogen transformers and dimmers, where LEDs may flicker or fail to turn on. A halogen lamp will always work with these components, making it a safe choice for replacement.

12 V — transformer required

MR16 always operates on 12 V voltage. Most MR16 fixtures already have a built-in transformer. Check that the transformer power is at least 20 W — a smaller transformer will not be able to provide enough current for the lamp.

GU5.3 vs GU10

The MR16 lamp base is GU5.3 (two-pin, 5.3 mm distance). It is easily confused with GU10, which is a direct 230 V base. Check the fixture carefully — GU5.3 only works in a 12 V system, GU10 only in a 230 V system.

Service life — 4000 h

The 4000 h service life of the Decostar 51S is a good-quality halogen lifespan (common range is 2000–4000 h). This is significantly less than LED (25,000+ h). Be prepared for replacements or consider an LED upgrade of the entire system if changing the lamp is difficult.

Installation checklist

  1. Turn off the power at the main switch
  2. Let the old lamp cool down completely
  3. Do not touch the bulb with bare hands — finger oils damage the glass
  4. Use a clean cloth or glove
  5. Install the new lamp — fit the two pins into the slots
  6. Turn on the power and test
Power: 20W

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Delivery

We ship your order from our warehouse in Jyväskylä. Orders placed before 2 PM are usually shipped on the same day. Free delivery within Finland for orders over €150.

Warranty

Products purchased through Lumenled come with a manufacturer's warranty, supported by Lumenled in cooperation with the importer. You can find detailed warranty terms here: Warranty terms of our partners.

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Usein kysytyt kysymykset

What is the difference between MR16 GU5.3 and MR16 GU10 lamps?

Although both are "MR16" (same 50 mm diameter), their base and voltage are completely different:

  • MR16 GU5.3 (this one): 12 V low voltage, 5.3 mm two-pin base. Requires a transformer. Typically used in halogens and indoor spotlights.
  • MR16 GU10: 230 V direct to mains, 10 mm two-pin base with a twist-and-lock mechanism. Does not require a transformer.

The lamps are not interchangeable. Check your fixture's base before purchasing — if unsure, carefully remove the old lamp and check the base type on the bottom (two thin pins = GU5.3, two thicker pins with a twist-lock = GU10).

Why might an MR16 LED be incompatible with an old transformer?

The compatibility of MR16 LED lamps with 12 V systems is a complex subject. Common problems:

  • Halogen transformers produce AC voltage: some LED MR16s do not support AC input — they may flicker or fail to work
  • Low load: an LED consumes so little power that an old transformer may not "detect" the load and will shut down
  • Electronic vs. magnetic transformer: both can cause different problems for LED lamps
  • Dimming: old dimmers rarely work optimally with LED MR16s

A halogen lamp always connects to an old system without issues. This makes halogen a good choice when only the lamp has broken and you do not want to replace the entire lighting system.

What is the importance of UV protection?

In addition to visible light, incandescent and halogen bulbs also produce ultraviolet (UV) radiation. UV is harmful to many materials:

  • Paints, colored fabrics, and paper fade
  • Plastics can yellow and become brittle
  • Human skin can suffer mild, irreversible damage with sufficiently long exposure

A UV-protected bulb — such as the Decostar 51S — contains a special coating on the glass that filters out the most harmful UV radiation. This is particularly important for:

  • Lighting artworks and antique furniture
  • Store lighting (protecting product colors)
  • Lighting children's rooms

LED lamps typically do not produce significant UV radiation.

Why shouldn't you touch the glass part of a halogen lamp with bare hands?

The glass of a halogen lamp becomes extremely hot during use (over 200 °C). If skin oils get onto the glass surface during installation, they will burn on and:

  • Weaken the glass — localized heating can cause the glass to crack
  • Shorten the service life — uneven heating puts stress on the filament

Use a clean cloth or gloves when changing the lamp. If you leave fingerprints on the glass, wipe it carefully with alcohol before installation.