Product reference

Logitech Signature Comfort M840 L

🇺🇸 United States Released 2026-06-01 USD 39.99 Signature Comfort Plus gen 1

AI score medium confidence

A wireless office mouse sharing the Signature Comfort Plus ergonomic profile and quiet clicks, without the M850 L's palm cushion.

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AI score breakdown

scored as mice

Sensor Performance 28%

Ergonomics 24%

Latency 18%

Build Quality 14%

Battery Life 6%

Value 10%

Its standout strength is battery life — a single AA cell rated for up to two years is best-in-class for the category. Its biggest weakness is latency, since it's Bluetooth-only with no low-latency USB receiver option, and it lacks the palm cushion found on Logitech's own higher-tier Comfort Plus model.

The overall score is the weighted average of these criteria — not a separate judgement. AI-generated scores are not hands-on test results. Percentages show each criterion's weight for this product type.

Scoring details

AI model: 23c86e4a-c769-43c0-a056-79e3cd15834f
Generated: 2026-07-31