Convoy M21B vs Olight Seeker Ultra size comparison
The Olight Seeker Ultra is 3.5 mm (0.14 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 Ultra is 3.5 mm (0.14 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 Ultra Check price ↗ | |
| Length | 141.5 mm (5.57 in) | 138 mm (5.43 in)−3.5 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 | 220 g with battery |
| Battery | 21700 | 21700 |
| Max output | — | 4,800 lm |
| Throw | — | 265 m |
| Type | EDC | EDC |
| Price | $48.99 at flashlightgo.com, as of Nov 4, 2026 | $169.99 at olight.com, as of Nov 4, 2026 |
| Source | flashlightgo.com sourced Output depends on LED option | olight.com sourced Body diameter and throw from Battery Junction |
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M21B vs Seeker Ultra: how they differ
Size and weight
The Olight Seeker Ultra is the shorter light: 138 mm (5.43 in) against 141.5 mm (5.57 in), a difference of 3.5 mm (2%). At its widest point the Olight Seeker Ultra is 0.7 mm slimmer (35 vs 35.7 mm). Weights are published on different bases (Convoy M21B: 120 g listed; Olight Seeker Ultra: 220 g with battery), so they are not directly comparable.
Brightness and throw
The Olight Seeker Ultra is rated at 4,800 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.
Price
When we checked on Nov 4, 2026, the Convoy M21B was $48.99 at flashlightgo.com and the Olight Seeker Ultra $169.99 at olight.com, so the Convoy M21B cost $121.00 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 Olight Seeker Ultra if you want a shorter light (3.5 mm shorter). On the specs we track, the Olight Seeker Ultra 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 Ultra
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M21B vs Seeker Ultra FAQ
Which is smaller, the Convoy M21B or the Olight Seeker Ultra?
The Olight Seeker Ultra is the shorter light: 138 mm (5.43 in) against 141.5 mm (5.57 in), a difference of 3.5 mm (2%). At its widest point the Olight Seeker Ultra is 0.7 mm slimmer (35 vs 35.7 mm). Weights are published on different bases (Convoy M21B: 120 g listed; Olight Seeker Ultra: 220 g with battery), so they are not directly comparable.
Which is cheaper, the Convoy M21B or the Olight Seeker Ultra?
When we checked on Nov 4, 2026, the Convoy M21B was $48.99 at flashlightgo.com and the Olight Seeker Ultra $169.99 at olight.com, so the Convoy M21B cost $121.00 less. Prices change often, so check the current price before you buy.
Do the Convoy M21B and Olight Seeker Ultra 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 Ultra 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 Ultra: specs from Olight product page (manufacturer). Price $169.99 from olight.com, checked Nov 4, 2026; prices change often.
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