R7s 78mm LED Bulbs (J78 Replacement)

R7s 78mm LEDs replace double ended J78 halogen tubes. Fit and lumens matter most.

Updated Oct 20, 2026. Edited by: Ilyass Ben Hakim.

Where to buy

Lighting stores stock branded R7s LEDs from Osram, Philips and Sylvania. Marketplaces sell cheaper generic packs. Search for J78 too, since sellers use both names.

Professional insight

Electricians match length, lumens and diameter before wattage. Then they confirm the fitting's dimmer and enclosure.

Measure contact to contact, not the glass length.
Fat LED bodies may not clear narrow reflector guards.
Enclosed fittings trap heat and shorten LED life.
Most R7s LEDs flicker or buzz on old dimmers.

Check the label

Length says 78mm, also written J78 or R7s 78.
Lumen output is printed, not just a watt equivalent.
Color temperature in kelvin, such as 3000K or 4000K.
Body diameter is given in millimeters.
Dimmable or non-dimmable is stated clearly.
Voltage matches your supply, 120V or 220 to 240V.
Safety marks such as UL, CE or UKCA appear.
Use in enclosed fittings is allowed or banned.

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Specs to match

R7s lamp lengths and typical LED use
Length	Also called	Typical halogen it replaces
78mm	J78	Up to about 150W
118mm	J118	Higher output floodlights
189mm	J189	Large work and stadium lamps

A 118mm lamp will not fit a 78mm holder. Pins sit at both ends, so the length must match exactly.

Features to look for

Lumen figure close to the light you have now.
Offset pins or slim body for tight holders.
CRI of 80 or higher for indoor rooms.
Wide beam angle for floodlights and uplighters.
Fan-free design if the fitting is silent now.

Watt equivalent claims vary widely between brands. Compare the lumen figure printed on each box instead.

Setup tips

1Turn off the circuit and wait for the old tube to cool.
2Open the fitting guard and press one end spring.
3Remove the old tube and check the end contacts.
4Fit the LED so both pins seat firmly.
5Close the guard and test before final mounting.

Common questions

Are R7s 78mm LEDs dimmable?: Some are. Many are not. Buy one marked dimmable and check your dimmer type.
Will an R7s LED fit my floodlight?: Only if length and diameter both fit. Measure the space around the tube.
Can I use R7s LEDs outdoors?: Yes, inside a fitting rated for outdoor use. The bulb itself is not weatherproof.