Convoy M21B vs Olight Seeker 4 size comparison
The Olight Seeker 4 is 7.5 mm (0.30 in) shorter than the Convoy M21B, and 0.7 mm narrower at its widest point. Weights are published on different bases (with battery vs listed), so compare them with care.
The Olight Seeker 4 is 7.5 mm (0.30 in) shorter than the Convoy M21B, and 0.7 mm narrower at its widest point. Weights are published on different bases (with battery vs listed), so compare them with care.
Dimensions
| Convoy M21B Check price ↗ | Olight Seeker 4 Check price ↗ | |
| Length | 141.5 mm (5.57 in) | 134 mm (5.28 in)−7.5 mm |
| Head / width | 35.7 mm (1.41 in) | 35 mm (1.38 in)−0.7 mm |
| Body | 27.1 mm (1.07 in) | 28 mm (1.10 in)+0.9 mm |
| Weight | 120 g listed | 205 g with battery |
| Battery | 21700 | 21700 |
| Max output | — | 3,100 lm |
| Throw | — | — |
| Type | EDC | EDC not on olight.com (US) |
| Price | $48.99 at flashlightgo.com, as of Nov 4, 2026 | not verified yet |
| Source | flashlightgo.com sourced Output depends on LED option | batteryjunction.com sourced Retailer lists 400 m throw, which conflicts with Olight figures for the series; throw omitted |
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M21B vs Seeker 4: how they differ
Size and weight
The Olight Seeker 4 is the shorter light: 134 mm (5.28 in) against 141.5 mm (5.57 in), a difference of 7.5 mm (5%). At its widest point the Olight Seeker 4 is 0.7 mm slimmer (35 vs 35.7 mm). Weights are published on different bases (Convoy M21B: 120 g listed; Olight Seeker 4: 205 g with battery), so they are not directly comparable.
Brightness and throw
The Olight Seeker 4 is rated at 3,100 lm; we have no published maximum for the Convoy M21B. Output for the Convoy M21B depends on the LED option chosen.
Battery
Both run on a removable 21700 battery, so spare cells work in either light.
Type
Both are EDC lights in our catalog with a tube body.
Which should you buy?
Choose the Olight Seeker 4 if you want a shorter light (7.5 mm shorter). On the specs we track, the Olight Seeker 4 is ahead or level everywhere; the Convoy M21B 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 ↗ Convoy M21B Check price ↗ Olight Seeker 4
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M21B vs Seeker 4 FAQ
Which is smaller, the Convoy M21B or the Olight Seeker 4?
The Olight Seeker 4 is the shorter light: 134 mm (5.28 in) against 141.5 mm (5.57 in), a difference of 7.5 mm (5%). At its widest point the Olight Seeker 4 is 0.7 mm slimmer (35 vs 35.7 mm). Weights are published on different bases (Convoy M21B: 120 g listed; Olight Seeker 4: 205 g with battery), so they are not directly comparable.
Do the Convoy M21B and Olight Seeker 4 use the same battery?
Both run on a removable 21700 battery, so spare cells work in either light.
Compare Convoy M21B with similar lights
Compare Olight Seeker 4 with similar lights
More
Sources
- Convoy M21B: specs from manufacturer published specs as listed by flashlightgo.com. Price $48.99 from flashlightgo.com, checked Nov 4, 2026; prices change often.
- Olight Seeker 4: specs from manufacturer published specs as listed by batteryjunction.com. No verified price yet.
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