Emisar D4K vs Sofirn SC31 Pro size comparison
The Sofirn SC31 Pro is 14.5 mm (0.57 in) longer than the Emisar D4K, and 2.6 mm narrower at its widest point. It is 1 g heavier (without battery).
The Sofirn SC31 Pro is 14.5 mm (0.57 in) longer than the Emisar D4K, and 2.6 mm narrower at its widest point. It is 1 g heavier (without battery).
Dimensions
| Emisar D4K Check price ↗ | Sofirn SC31 Pro Check price ↗ | |
| Length | 103 mm (4.06 in) | 117.5 mm (4.63 in)+14.5 mm |
| Head / width | 28 mm (1.10 in) | 25.4 mm (1.00 in)−2.6 mm |
| Body | 26.5 mm (1.04 in) | — |
| Weight | 58 g without battery | 59 g without battery+1 g |
| Battery | 21700 | 18650 |
| Max output | — | 2,000 lm |
| Throw | — | — |
| Type | EDC | EDC |
| Price | $39.69 at intl-outdoor.com, as of Nov 4, 2026 | not verified yet |
| Source | intl-outdoor.com sourced Output depends on LED option | sofirnlight.com sourced Only head diameter listed |
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D4K vs SC31 Pro: how they differ
Size and weight
The Emisar D4K is the shorter light: 103 mm (4.06 in) against 117.5 mm (4.63 in), a difference of 14.5 mm (12%). At its widest point the Sofirn SC31 Pro is 2.6 mm slimmer (25.4 vs 28 mm). The Emisar D4K is 1 g lighter (58 g vs 59 g, without battery).
Brightness and throw
The Sofirn SC31 Pro is rated at 2,000 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 Sofirn SC31 Pro runs on a removable 18650 battery. For scale, a 21700 cell is about 21 × 70 mm and a 18650 about 18 × 65 mm (nominal).
Type
Both are EDC lights in our catalog with a tube body.
Which should you buy?
Choose the Emisar D4K if you want a shorter light (14.5 mm shorter). Choose the Sofirn SC31 Pro if you want a slimmer profile (2.6 mm narrower). We compare published size, weight, output, throw and battery only, not runtime, interface or build quality.
Check price ↗ Emisar D4K Check price ↗ Sofirn SC31 Pro
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D4K vs SC31 Pro FAQ
Which is smaller, the Emisar D4K or the Sofirn SC31 Pro?
The Emisar D4K is the shorter light: 103 mm (4.06 in) against 117.5 mm (4.63 in), a difference of 14.5 mm (12%). At its widest point the Sofirn SC31 Pro is 2.6 mm slimmer (25.4 vs 28 mm). The Emisar D4K is 1 g lighter (58 g vs 59 g, without battery).
Do the Emisar D4K and Sofirn SC31 Pro use the same battery?
The Emisar D4K runs on a removable 21700 battery; the Sofirn SC31 Pro runs on a removable 18650 battery. For scale, a 21700 cell is about 21 × 70 mm and a 18650 about 18 × 65 mm (nominal).
Compare Emisar D4K with similar lights
Compare Sofirn SC31 Pro with similar lights
More
Sources
- Emisar D4K: specs from Emisar product page (manufacturer). Price $39.69 from intl-outdoor.com, checked Nov 4, 2026; prices change often.
- Sofirn SC31 Pro: specs from manufacturer published specs as listed by sofirnlight.com. No verified price yet.
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