Sylvania RefLED Retro MR11 GU5.3 4W 345lm 36° 12V – glass body, replaces 35W

MR11 size with GU5.3 base — a unique combination

The dimensions of most GU5.3 base spotlights are:

• Standard MR16: diameter 51 mm, base GU5.3 — the most common
• This Sylvania special model: diameter 35 mm (MR11 size), base GU5.3 — rarer
• Standard MR11: diameter 35 mm, base GU4 (4 mm pins) — different

This Sylvania model is suitable for fixtures that have:

• A GU5.3 base but where the lamp housing is smaller than 51 mm
• Custom-made (e.g., imported from the USA) fixtures
• Vintage and retro-style fixtures where the small lamp size is part of the aesthetic
• Smaller spotlights and display cabinets

Check the lamp dimensions before ordering — measure the diameter of your existing halogen to ensure compatibility.

Requires a 12V transformer

This is a 12V low-voltage lamp that requires a 12V transformer to operate. This Sylvania model is compatible with both:

• Magnetic transformers (traditional, heavier) — common in older light fixtures
• Electronic transformers — lightweight, more modern technology, in almost all new fixtures

Compatibility with electronic transformers depends on the exact model of the transformer — not all may work with this LED bulb. The most common compatible brands are Helvar, Tridonic, Osram, Ledvance, and Vossloh-Schwabe.

You can find compatible transformers in the Electrical Supplies → Transformers category.

Check the transformer wattage

The transformer's wattage must match the lamp (or the combined wattage of multiple lamps). For one 4W lamp, the transformer should be at least about 5W (reserve a small margin). For multiple lamps:

• 2 lamps = 8W → transformer at least 10W
• 5 lamps = 20W → transformer at least 25W
• 10 lamps = 40W → transformer at least 50W

Glass body — premium quality

Unlike regular plastic LED bulbs, this Sylvania RefLED Retro has a full glass body — the same material as traditional halogen bulbs:

• More even light distribution than plastic
• No yellowing over time
• Halogen-like appearance — fits seamlessly into old fixtures
• Withstands higher temperatures than plastic

Replaces 35W GU5.3 halogen — 89% energy saving

This 4W LED produces the same light output as a traditional 35W GU5.3 halogen. Energy savings are approximately 89%, and the lifespan is:

• 35W GU5.3 halogen: 2,000–4,000 h
• This Sylvania RefLED Retro: 15,000 h — 4–7 times longer

In addition, the 50,000 switching cycles make this an excellent option for fixtures that are switched on and off frequently (e.g., motion-sensor lights, bathrooms, storage rooms).

This lamp is not dimmable

Do not install the lamp in a fixture equipped with a dimmer. The lamp may flicker, stay on at full brightness, or be damaged.

36° beam angle — wide spotlight

This lamp's 36° beam angle is a "flood" category — a wide spotlight suitable for:

• General lighting in small spaces
• Ambient lighting in hotels, restaurants, and bars
• Small spotlights and display cabinet lights
• Chandeliers and multi-lamp fixtures where the MR11 size fits

Installation checklist

1. Check that the fixture has a GU5.3 base (not GU4 or GU10)
2. Measure the diameter of the lamp housing — 35 mm of space is required (not larger MR16 space)
3. Check that a 12V transformer is being used (magnetic or electronic)
4. Check that the transformer's wattage is sufficient for the total wattage of the lamps
5. Check that the fixture does not have a dimmer
6. Turn off the power before installation — do not touch the lamp glass with your fingers
7. Install the lamp and turn on the power

Also check out the other GU5.3 LED spotlights in our selection.