Emisar D4K vs RovyVon S3 Pro size comparison
The RovyVon S3 Pro is 16 mm (0.63 in) longer than the Emisar D4K, and 1 mm wider at its widest point. Weights are published on different bases (listed vs without battery), so compare them with care.
The RovyVon S3 Pro is 16 mm (0.63 in) longer than the Emisar D4K, and 1 mm wider at its widest point. Weights are published on different bases (listed vs without battery), so compare them with care.
Dimensions
| Emisar D4K Check price ↗ | RovyVon S3 Pro Check price ↗ | |
| Length | 103 mm (4.06 in) | 119 mm (4.69 in)+16 mm |
| Head / width | 28 mm (1.10 in) | 29 mm (1.14 in)+1 mm |
| Body | 26.5 mm (1.04 in) | 29 mm (1.14 in)+2.5 mm |
| Weight | 58 g without battery | 150 g listed |
| Battery | 21700 | 18650 |
| Max output | — | 2,800 lm |
| Throw | — | 130 m |
| Type | EDC | EDC |
| Price | $39.69 at intl-outdoor.com, as of Nov 4, 2026 | from $79.95 at batteryjunction.com, as of Nov 4, 2026 |
| Source | intl-outdoor.com sourced Output depends on LED option | batteryjunction.com sourced |
We may earn a commission from these links, at no cost to you. Rankings are never paid for. Disclosure
D4K vs S3 Pro: how they differ
Size and weight
The Emisar D4K is the shorter light: 103 mm (4.06 in) against 119 mm (4.69 in), a difference of 16 mm (13%). At its widest point the Emisar D4K is 1 mm slimmer (28 vs 29 mm). Weights are published on different bases (Emisar D4K: 58 g without battery; RovyVon S3 Pro: 150 g listed), so they are not directly comparable.
Brightness and throw
The RovyVon S3 Pro is rated at 2,800 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 RovyVon S3 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).
Price
When we checked on Nov 4, 2026, the Emisar D4K was $39.69 at intl-outdoor.com and the RovyVon S3 Pro from $79.95 at batteryjunction.com, so the Emisar D4K cost $40.26 less. Prices change often, so check the current price before you buy.
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 (16 mm shorter). On the specs we track, the Emisar D4K is ahead or level everywhere; the RovyVon S3 Pro makes sense mainly if its price, interface or a feature we don't track suits you better. We compare published size, weight, output, throw and battery only, not runtime, interface or build quality.
Check price ↗ Emisar D4K Check price ↗ RovyVon S3 Pro
We may earn a commission from these links, at no cost to you. Rankings are never paid for. Disclosure
D4K vs S3 Pro FAQ
Which is smaller, the Emisar D4K or the RovyVon S3 Pro?
The Emisar D4K is the shorter light: 103 mm (4.06 in) against 119 mm (4.69 in), a difference of 16 mm (13%). At its widest point the Emisar D4K is 1 mm slimmer (28 vs 29 mm). Weights are published on different bases (Emisar D4K: 58 g without battery; RovyVon S3 Pro: 150 g listed), so they are not directly comparable.
Which is cheaper, the Emisar D4K or the RovyVon S3 Pro?
When we checked on Nov 4, 2026, the Emisar D4K was $39.69 at intl-outdoor.com and the RovyVon S3 Pro from $79.95 at batteryjunction.com, so the Emisar D4K cost $40.26 less. Prices change often, so check the current price before you buy.
Do the Emisar D4K and RovyVon S3 Pro use the same battery?
The Emisar D4K runs on a removable 21700 battery; the RovyVon S3 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 RovyVon S3 Pro 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.
- RovyVon S3 Pro: specs from manufacturer published specs as listed by batteryjunction.com. Drawing: outline from published specs. Price from $79.95 from batteryjunction.com, checked Nov 4, 2026; prices change often.
Found an error? Email [email protected] and we will fix it.