Emisar D4K vs Olight ArkPro Ultra size comparison
The Olight ArkPro Ultra is 21 mm (0.83 in) longer than the Emisar D4K, and 1 mm narrower at its widest point. Weights are published on different bases (with battery vs without battery), so compare them with care.
Olight ArkPro Ultra: Photo: Olight · Image policy
The Olight ArkPro Ultra is 21 mm (0.83 in) longer than the Emisar D4K, and 1 mm narrower at its widest point. Weights are published on different bases (with battery vs without battery), so compare them with care.
Dimensions
| Emisar D4K Check price ↗ | Olight ArkPro Ultra Check price ↗ | |
| Length | 103 mm (4.06 in) | 124 mm (4.88 in)+21 mm |
| Head / width | 28 mm (1.10 in) | 27 mm (1.06 in)−1 mm |
| Body | 26.5 mm (1.04 in) | — |
| Thickness | — | 16 mm (0.63 in) |
| Weight | 58 g without battery | 120 g with battery |
| Battery | 21700 | Built-in |
| Max output | — | 1,700 lm |
| Throw | — | 205 m |
| Type | EDC | EDC |
| Price | $39.69 at intl-outdoor.com, as of Nov 4, 2026 | $129.99 at olight.com, as of Nov 4, 2026 |
| Source | intl-outdoor.com sourced Output depends on LED option | olight.com sourced |
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D4K vs ArkPro Ultra: how they differ
Size and weight
The Emisar D4K is the shorter light: 103 mm (4.06 in) against 124 mm (4.88 in), a difference of 21 mm (17%). At its widest point the Olight ArkPro Ultra is 1 mm slimmer (27 vs 28 mm). Weights are published on different bases (Emisar D4K: 58 g without battery; Olight ArkPro Ultra: 120 g with battery), so they are not directly comparable.
Brightness and throw
The Olight ArkPro Ultra is rated at 1,700 lm; we have no published maximum for the Emisar D4K. Output for the Emisar D4K depends on the LED option chosen.
Battery
The Emisar D4K runs on a removable 21700 battery; the Olight ArkPro Ultra runs on a built-in rechargeable battery. Only the Emisar D4K lets you swap in a charged spare.
Price
When we checked on Nov 4, 2026, the Emisar D4K was $39.69 at intl-outdoor.com and the Olight ArkPro Ultra $129.99 at olight.com, so the Emisar D4K cost $90.30 less. Prices change often, so check the current price before you buy.
Type
Both are EDC lights in our catalog.
Which should you buy?
Choose the Emisar D4K if you want a shorter light (21 mm shorter) and a removable cell you can swap. Choose the Olight ArkPro Ultra if you want a built-in battery with no separate cell to buy. We compare published size, weight, output, throw and battery only, not runtime, interface or build quality.
Check price ↗ Emisar D4K Check price ↗ Olight ArkPro Ultra
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D4K vs ArkPro Ultra FAQ
Which is smaller, the Emisar D4K or the Olight ArkPro Ultra?
The Emisar D4K is the shorter light: 103 mm (4.06 in) against 124 mm (4.88 in), a difference of 21 mm (17%). At its widest point the Olight ArkPro Ultra is 1 mm slimmer (27 vs 28 mm). Weights are published on different bases (Emisar D4K: 58 g without battery; Olight ArkPro Ultra: 120 g with battery), so they are not directly comparable.
Which is cheaper, the Emisar D4K or the Olight ArkPro Ultra?
When we checked on Nov 4, 2026, the Emisar D4K was $39.69 at intl-outdoor.com and the Olight ArkPro Ultra $129.99 at olight.com, so the Emisar D4K cost $90.30 less. Prices change often, so check the current price before you buy.
Do the Emisar D4K and Olight ArkPro Ultra use the same battery?
The Emisar D4K runs on a removable 21700 battery; the Olight ArkPro Ultra runs on a built-in rechargeable battery. Only the Emisar D4K lets you swap in a charged spare.
Compare Emisar D4K with similar lights
Compare Olight ArkPro Ultra with similar lights
More
Sources
- Emisar D4K: specs from Emisar product page (manufacturer). Drawing: outline from published specs. Price $39.69 from intl-outdoor.com, checked Nov 4, 2026; prices change often.
- Olight ArkPro Ultra: specs from Olight product page (manufacturer). Photo from manufacturer: the maker's own product photo with the background removed, scaled to the published length and diameter (Photo: Olight; image policy). Price $129.99 from olight.com, checked Nov 4, 2026; prices change often.
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