The BesYouSel 400W R7S bulb is the closest match for buyers specifically seeking a 400-watt, 118 mm halogen bulb. The other options below use different wattages, so they are alternatives only if your fixture allows them. These listings describe linear bulbs for lighting applications; they do not establish compatibility with every heater. Check your appliance’s manual and socket requirements before buying.
| Product | Wattage | Pack | Best for |
|---|---|---|---|
| BesYouSel R7S | 400W | 5 | Matching a 400W, 118 mm R7S specification |
| CTKcom J Type | 500W | 5 | Buyers whose fixture specifies 500W |
| Comyan R7S | 300W | 4 | Buyers whose fixture specifies 300W |
| Jaenmsa R7S | 500W | 6 | Buyers needing a six-bulb 500W pack |
| Jaenmsa R7S | 300W | 5 | Buyers needing a five-bulb 300W pack |
BesYouSel 400W R7S 118mm Bulbs
Best for: Buyers whose existing fixture calls for a 400W, 118 mm, double-ended R7S bulb. This five-pack is the only listed option that matches the requested 400W wattage.
The product listing specifies 400W, AC 110–130V, 6000 lumens, 2700K warm white, dimmability, and a 360-degree beam angle. It has a J-type R7S base and is listed as 118 mm long. The manufacturer describes it for work, security, and landscape lighting.
Why it was selected: Its stated wattage and length directly match the search intent, while its voltage range covers common 120V household supply according to the listing.
Limitation: The listing identifies lighting uses, not heater-appliance compatibility. It also says the bulb is for a 118 mm base, not a 78 mm base. Confirm your appliance’s exact specification before purchase.
CTKcom 500W J Type Bulbs
Best for: Buyers whose fixture specifies a 500W, 118 mm R7S bulb rather than 400W. This five-pack is a higher-wattage alternative, not a direct 400W replacement.
The listing describes double-ended T3 halogen bulbs with an R7S base, 120V operating voltage, and a length of 118 mm (also given as 4.71 inches). It states an approximate bulb life of 2,000 hours and says the bulbs work with 110V, 120V, and 130V.
Why it was selected: The base style and length are similar to the 400W option, making it useful for comparison when a buyer’s appliance specifies 500W. Its listed voltage range also makes the electrical rating easy to check against a fixture label.
Limitation: At 500W, it does not match a 400W requirement. Do not assume a higher-wattage bulb is safe in a fixture rated for 400W; follow the appliance’s maximum wattage specification.
Comyan 300W R7S Bulbs
Best for: Buyers whose fixture specifies 300W and a compatible 118 mm R7S bulb. The four-pack is a lower-wattage alternative for the right appliance, but it is not a substitute for a 400W bulb when that wattage is required.
Comyan lists these bulbs at 300W and 120V, with 4500 lumens, 2700K warm white light, dimmability, and a full 360-degree beam angle. The product description names applications including floodlights, work and security lights, floor lamps, and landscape lighting.
Why it was selected: It provides a useful lower-wattage comparison for shoppers who discovered that their fixture’s label calls for 300W rather than 400W. Its listing clearly states voltage, light output, and dimming capability.
Limitation: It is 300W, not 400W. The available product information does not establish suitability for a heater, so check the appliance manual and bulb dimensions before ordering.
Jaenmsa 500W Six-Pack R7S Bulbs
Best for: Buyers with a compatible 500W fixture who prefer a six-bulb pack. The listing specifies a 118 mm J-type double-ended base, making length and base details straightforward to compare with an existing bulb.
The product description gives a 500W rating, 120V voltage, 2700K warm-white color, dimmability, and a 360-degree beam angle. It also states a 0.39-inch diameter and 4.6-inch length, and describes the bulbs as having 22,500 lumens. The listing says they contain no lead or mercury and produce no UV or IR radiation.
Why it was selected: It is another clearly specified 118 mm R7S option for shoppers whose fixture requires 500W, and the six-pack quantity distinguishes it from the other listed packs.
Limitation: This is a 500W product, so it is not a direct match for a fixture requiring 400W. The listing’s stated light output should not be treated as proof of heater compatibility.
Jaenmsa 300W Five-Pack R7S Bulbs
Best for: Buyers whose appliance or lighting fixture specifies 300W and a 118 mm R7S bulb, especially those looking for a five-pack.
Jaenmsa lists these bulbs as 300W, 120V, 2700K warm white, and dimmable. The product description states 13,500 lumens, a 360-degree beam angle, a 0.39-inch diameter, and a 4.6-inch length. It describes a J118 double-ended base and says the bulbs contain no lead or mercury and emit no UV or IR radiation.
Why it was selected: It offers a second 300W comparison with a different pack quantity and listed light output. It may suit a buyer who has confirmed that 300W—not 400W—is the correct rating for the fixture.
Limitation: Its wattage is 100W below the requested 400W. Do not select it based only on similar length or socket style; the appliance’s required wattage must also match.
Buying Guide: How to Choose a Halogen Bulb
Does your appliance actually require a 400W bulb?
Start with the appliance label, manual, or the markings on the original bulb. Match the stated wattage rather than choosing a bulb based on appearance. A 300W bulb and a 500W bulb are not interchangeable with a 400W bulb simply because they may share an R7S base or similar length.
This distinction matters especially for heater appliances. The products listed here are described primarily as lighting bulbs. Their descriptions do not verify fit or safe operation in a particular heater. If the manufacturer specifies a heater-only replacement bulb or a particular part number, use that information to guide the purchase.
What does R7S 118mm mean?
R7S refers to a double-ended base style used by linear bulbs. The 118 mm measurement describes the nominal length category in these listings. A bulb that is too long or too short may not fit between the fixture contacts. Measure the old bulb and check the fixture’s required length before ordering.
Do not confuse 118 mm bulbs with shorter 78 mm versions. The 400W BesYouSel listing explicitly says it is for a 118 mm base and not a 78 mm base. Verify both the socket type and length, not just the wattage.
How should voltage and wattage be compared?
Check the voltage printed on the fixture or specified in its manual. The products listed here state either 120V or a range that includes 120V, but the correct choice still depends on the appliance. Wattage is a separate requirement: matching voltage does not make a bulb with the wrong wattage suitable.
For the exact 400W search, the BesYouSel option lists 400W and AC 110–130V. The other products listed are 300W or 500W. Choose those alternatives only if your appliance calls for the corresponding wattage.
Does brightness or color temperature matter?
For a lighting fixture, compare the listed lumen output and color temperature with your needs. The 400W BesYouSel bulb is listed at 6000 lumens and 2700K warm white. The other products list outputs from 4500 to 22,500 lumens, depending on the product. Those figures describe claimed light output; they do not indicate how much heat a heater produces.
For a heater, brightness may not be the main selection criterion. The replacement must meet the appliance’s stated electrical and physical specifications. Do not infer heater performance from a bulb’s lumen rating or warm-white color description.
Do you need a dimmable bulb?
Several listings describe their bulbs as dimmable. This feature is relevant only when the fixture has a compatible dimmer and the appliance instructions permit dimming. A dimmable bulb does not guarantee that every dimmer or heater control will work with it.
How many bulbs should you buy?
Consider the pack size and whether you need a spare, but confirm the specifications before choosing based on quantity. The listed options come in packs of four, five, or six. A larger pack is not useful if its wattage or length is wrong for the fixture.
Frequently Asked Questions
Which listed bulb is actually 400W?
The BesYouSel R7S 118 mm product is listed as 400W. The other four options are listed as either 300W or 500W.
Can I use a 500W bulb in place of a 400W bulb?
Do not assume that you can. Use only the wattage permitted by the fixture or appliance manufacturer. A 500W bulb is not a direct replacement for a 400W specification.
Can I use a 300W bulb instead of a 400W bulb?
Only if the appliance manufacturer allows a 300W bulb. The 300W listings are not direct 400W replacements, even if their base and length appear similar.
Are these bulbs confirmed to work in halogen heaters?
No. The supplied product descriptions focus on lighting applications and do not confirm compatibility with specific heater models. Check the heater manual or manufacturer’s replacement-part guidance before buying.
How can I tell whether I need 78 mm or 118 mm?
Check the original bulb, fixture label, or appliance manual, and measure the required bulb length. The 400W product in this list is specified for 118 mm, not 78 mm.
Is R7S the same as 118 mm?
No. R7S identifies the base style, while 118 mm identifies the bulb length category. Confirm both details, along with wattage and voltage, before purchase.