Convoy M21B vs Olight Seeker 4 Pro size comparison

By · Updated · How we compare and rank

The Olight Seeker 4 Pro is 8.5 mm (0.33 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.

Convoy M21B · 141.5 mmOlight Seeker 4 Pro · 133 mm

The Olight Seeker 4 Pro is 8.5 mm (0.33 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 Pro
Check price ↗
Length141.5 mm (5.57 in)133 mm (5.24 in)−8.5 mm
Head / width35.7 mm (1.41 in)35 mm (1.38 in)−0.7 mm
Body27.1 mm (1.07 in)28 mm (1.10 in)+0.9 mm
Weight120 g listed205 g with battery
Battery2170021700
Max output—4,600 lm
Throw—260 m
TypeEDCEDC
Price$48.99 at flashlightgo.com, as of Nov 4, 2026$139.99 at olight.com, as of Nov 4, 2026
Sourceflashlightgo.com sourced
Output depends on LED option
olight.com sourced

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M21B vs Seeker 4 Pro: how they differ

Size and weight

The Olight Seeker 4 Pro is the shorter light: 133 mm (5.24 in) against 141.5 mm (5.57 in), a difference of 8.5 mm (6%). At its widest point the Olight Seeker 4 Pro is 0.7 mm slimmer (35 vs 35.7 mm). Weights are published on different bases (Convoy M21B: 120 g listed; Olight Seeker 4 Pro: 205 g with battery), so they are not directly comparable.

Brightness and throw

The Olight Seeker 4 Pro is rated at 4,600 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 4 Pro $139.99 at olight.com, so the Convoy M21B cost $91.00 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 4 Pro if you want a shorter light (8.5 mm shorter). On the specs we track, the Olight Seeker 4 Pro 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 Pro

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M21B vs Seeker 4 Pro FAQ

Which is smaller, the Convoy M21B or the Olight Seeker 4 Pro?

The Olight Seeker 4 Pro is the shorter light: 133 mm (5.24 in) against 141.5 mm (5.57 in), a difference of 8.5 mm (6%). At its widest point the Olight Seeker 4 Pro is 0.7 mm slimmer (35 vs 35.7 mm). Weights are published on different bases (Convoy M21B: 120 g listed; Olight Seeker 4 Pro: 205 g with battery), so they are not directly comparable.

Which is cheaper, the Convoy M21B or the Olight Seeker 4 Pro?

When we checked on Nov 4, 2026, the Convoy M21B was $48.99 at flashlightgo.com and the Olight Seeker 4 Pro $139.99 at olight.com, so the Convoy M21B cost $91.00 less. Prices change often, so check the current price before you buy.

Do the Convoy M21B and Olight Seeker 4 Pro use the same battery?

Both run on a removable 21700 battery, so spare cells work in either light.

Compare Convoy M21B with similar lights

M21B vs E40RM21B vs PD40R V3.0M21B vs Seeker UltraM21B vs TK16 V2.0M21B vs P20iXM21B vs LD35R

Compare Olight Seeker 4 Pro with similar lights

Seeker 4 Pro vs Seeker 3 ProSeeker 4 Pro vs Seeker 4Seeker 4 Pro vs EDC29Seeker 4 Pro vs E75Seeker 4 Pro vs E40RSeeker 4 Pro vs Seeker 3

More

Convoy M21B size & specsOlight Seeker 4 Pro size & specsBest 21700 flashlightsAll Convoy lightsAll Olight lightsBest EDC flashlights

Sources

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