Convoy M21H vs Olight Seeker 3 Pro size comparison
The Olight Seeker 3 Pro is 1.2 mm (0.05 in) longer than the Convoy M21H, and 5 mm narrower at its widest point.
The Olight Seeker 3 Pro is 1.2 mm (0.05 in) longer than the Convoy M21H, and 5 mm narrower at its widest point.
Dimensions
| Convoy M21H Check price ↗ | Olight Seeker 3 Pro Check price ↗ | |
| Length | 130.8 mm (5.15 in) | 132 mm (5.20 in)+1.2 mm |
| Head / width | 40 mm (1.57 in) | 35 mm (1.38 in)−5 mm |
| Body | 27 mm (1.06 in) | 28 mm (1.10 in)+1 mm |
| Tail | 28.5 mm (1.12 in) | — |
| Weight | — | 200 g with battery |
| Battery | 21700 | 21700 |
| Max output | — | 4,200 lm |
| Throw | — | 250 m |
| Type | EDC | EDC not on olight.com (US) |
| Price | from $44.95 at nealsgadgets.com, as of Nov 4, 2026 | $139.95 at batteryjunction.com, as of Nov 4, 2026 |
| Source | nealsgadgets.com sourced | batteryjunction.com sourced |
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M21H vs Seeker 3 Pro: how they differ
Size and weight
The Convoy M21H is the shorter light: 130.8 mm (5.15 in) against 132 mm (5.20 in), a difference of 1.2 mm (1%). At its widest point the Olight Seeker 3 Pro is 5 mm slimmer (35 vs 40 mm).
Brightness and throw
The Olight Seeker 3 Pro is rated at 4,200 lm; we have no published maximum for the Convoy M21H.
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 M21H was from $44.95 at nealsgadgets.com and the Olight Seeker 3 Pro $139.95 at batteryjunction.com, so the Convoy M21H cost $95.00 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 3 Pro if you want a slimmer profile (5 mm narrower). On the specs we track, the Olight Seeker 3 Pro is ahead or level everywhere; the Convoy M21H 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 M21H Check price ↗ Olight Seeker 3 Pro
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M21H vs Seeker 3 Pro FAQ
Which is smaller, the Convoy M21H or the Olight Seeker 3 Pro?
The Convoy M21H is the shorter light: 130.8 mm (5.15 in) against 132 mm (5.20 in), a difference of 1.2 mm (1%). At its widest point the Olight Seeker 3 Pro is 5 mm slimmer (35 vs 40 mm).
Which is cheaper, the Convoy M21H or the Olight Seeker 3 Pro?
When we checked on Nov 4, 2026, the Convoy M21H was from $44.95 at nealsgadgets.com and the Olight Seeker 3 Pro $139.95 at batteryjunction.com, so the Convoy M21H cost $95.00 less. Prices change often, so check the current price before you buy.
Do the Convoy M21H and Olight Seeker 3 Pro use the same battery?
Both run on a removable 21700 battery, so spare cells work in either light.
Compare Convoy M21H with similar lights
Compare Olight Seeker 3 Pro with similar lights
More
Sources
- Convoy M21H: specs from manufacturer published specs as listed by nealsgadgets.com. Price from $44.95 from nealsgadgets.com, checked Nov 4, 2026; prices change often.
- Olight Seeker 3 Pro: specs from manufacturer published specs as listed by batteryjunction.com. Price $139.95 from batteryjunction.com, checked Nov 4, 2026; prices change often.
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