DGBRSM 5pcs 4D 4.8V 0.75A Bayonet Base Krypton Replacement Bulb for Flashlight Replacement Bulb Torches Work Light Flashlight Bulbs

Why I reached for these bulbs

A few of my older 4D flashlights have been sitting idle for years, not because the bodies failed but because sourcing the right bulbs turned into a scavenger hunt. When I saw a simple pack of 4.8V, 0.75A krypton bayonet-base replacements, I picked them up to see if I could bring those torches back without resorting to LED conversions. I went in expecting a straightforward install, classic incandescent warmth, and serviceable brightness for household and workshop tasks. That’s exactly what I got—with a couple of nuances worth noting.

What you’re getting

These are basic, glass-and-metal krypton incandescent bulbs in a bayonet base, rated 4.8V at 0.75A. The pack includes five bulbs, which matters because incandescent filaments, while predictable, are consumables. If you’re maintaining a few old lights or keep a bulb in your toolbox or glove compartment, having spares on hand is practical.

A quick reminder on the format: bayonet bases install with a push-and-quarter-turn action. If your flashlight uses a screw-in Edison mini base or a pre-focus PR flange, these won’t fit. Check your socket before you order.

Installation and compatibility

Installation was genuinely easy. I removed the bezels and reflectors on two older 4D lantern-style flashlights and one compact work light, lined up the bayonet pins, pressed in, and turned until they clicked. Contact alignment was reliable across all three fixtures; I didn’t need to bend springs or fuss with the socket. Polarity isn’t a concern with incandescent bulbs, so it’s hassle-free.

Voltage deserves attention. These bulbs are rated at 4.8V. They ran fine on my 4D-cell lights, which nominally present around 6V on fresh alkalines and sag under load. Expect a bright initial output and, potentially, a shorter bulb life if you’re feeding them consistently higher than their rating. If your light runs on rechargeable cells with a lower nominal voltage, they still work, just a bit dimmer. Bottom line: they’re a drop-in for many older 4D torches, but if your light is unusually hot on bulbs, consider stepping to a bulb rated closer to 6V.

Performance and beam quality

In use, these krypton bulbs deliver exactly what incandescent enthusiasts expect:

• A warm, yellowish beam that’s comfortable on the eyes and easy on color rendering for natural materials and paper maps.
• A smooth hotspot with a soft spill, particularly when paired with classic deep reflectors. They don’t produce the hard-edged artifacts you sometimes see with budget LEDs.
• Immediate full output without ramp-up.

In a dark garage and in the yard at night, I had no trouble navigating, finding hardware on shelves, or checking tire sidewalls. The beam feels generous rather than laser-focused—the throw is decent for a yard, while the spill makes close work pleasant. If you’re accustomed to modern LED throwers, these won’t punch nearly as far, but they’re friendlier at close range and less fatiguing for prolonged tasks.

Brightness is adequate for general use. I didn’t instrument these with a light meter, but compared with common budget LED drop-ins, the krypton output is lower while looking “richer” due to the warm tone. If you associate brightness solely with lumen numbers, you might find them modest. If you value a cohesive, glare-free beam for practical chores, they’re satisfying.

Power draw, heat, and runtime

At 0.75A, these aren’t gentle on D cells, but they’re also not egregious. Runtime is influenced by battery quality, ambient temperature, and how often you switch on and off. Across a few evenings of mixed use, I got several hours of what I’d call “usefully bright” light before the gradual incandescent dimming curve kicked in. That soft fade is a feature for some users—no sudden cutoff—and a minor annoyance for others who prefer regulated output.

Heat is noticeable. After extended use, the bulb runs hot and can warm the bezel area. That’s normal for incandescents, but it does mean you shouldn’t handle the glass immediately after switching off, and care is required if you’re working near delicate materials.

Durability and build

Glass thickness and base crimping look consistent, and fit across the five-bulb pack was uniform in my sockets. Filament bulbs are inherently susceptible to shock; that’s physics, not a quality flaw. I drop-tested a flashlight with one of these installed from waist height onto a rubber mat—no failure. I wouldn’t push my luck on concrete or with repeated hard knocks. For vehicles or rough job sites, LEDs remain the more abuse-tolerant choice.

Because they’re krypton rather than halogen, handling oils on the glass aren’t the same concern. Even so, I avoid fingerprints—wiping the bulb with a clean cloth before installation is a good habit. The bulbs arrive adequately protected and none were DOA in my pack. Storing the extras in a small case or the original packaging is wise; they’re small enough to misplace and fragile enough to break if tossed loose into a drawer.

Everyday usability

In practice, these bulbs make older flashlights feel “right.” The start-up is instant, the beam is gentle, and the color makes wood, soil, and metal look natural. For tasks like checking breakers, looking under sinks, or walking to the shed, they’re perfectly serviceable. For search-and-rescue scenarios or wide-area illumination, you’ll notice the gap to modern LEDs.

One upside of sticking with incandescents in legacy lights is that your existing reflectors and focus mechanisms work as intended. Adjustable heads that never quite focused properly with LED retrofits behave predictably again. There’s also an authenticity aspect—if you’re maintaining vintage equipment, these preserve the look and feel that LEDs can’t replicate.

Who these are for

• Owners of bayonet-base 4D flashlights, lanterns, or work lights who want a reliable, period-correct replacement.
• Folks who prefer the warm, even beam of incandescents for close work and reading.
• Anyone maintaining emergency kits with D-cell devices and wanting off-the-shelf, easy-to-install spares.

Who should look elsewhere:

• Users needing maximum runtime, output, and ruggedness. A quality LED upgrade will outperform these in efficiency and durability.
• Those running higher-voltage or lithium-converted lights without regulation; verify compatibility or choose a bulb with a matching voltage rating.

Caveats and tips

• Verify your socket: These are bayonet base. If yours is a different style, they won’t seat.
• Mind the voltage: 4.8V rating is fine in many 4D setups, but sustained overvoltage can shorten life.
• Heat and safety: They get hot in use. Let them cool before handling, and keep spares out of reach of children—they’re small and breakable.
• Carry spares: Even with careful handling, vibration can end a filament’s life. A five-pack is practical insurance.

Value

The pack-of-five format is the right call. It brings the per-bulb cost down and acknowledges that incandescent bulbs are consumables. For the functionality they restore to sidelined lights, the value feels solid. You can choose LEDs to chase performance, but for users who simply want their old tools working as designed, these bulbs are an economical fix.

Recommendation

I recommend these krypton bayonet bulbs for anyone looking to revive bayonet-base 4D flashlights with a warm, comfortable beam and simple, no-fuss installation. They aren’t trying to compete with LEDs on output or efficiency—and they don’t need to. They excel at making classic lights usable again with predictable performance, realistic color, and a beam profile that’s kind to the eyes. If your priorities are authenticity, ease of use, and a practical fix for older gear, this five-pack is an easy yes. If you need modern brightness, long runtimes, and drop resistance above all, look to an LED conversion instead.