3M E-A-R UltraFit 340-4003 Cordless Earplugs Review

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Reviewed by Steven Eaton, WC Safety Editorial

The 3M E-A-R UltraFit 340-4003 Cordless Earplugs — NRR 25 is a ear plugs from 3M, listed on Amazon. This review restates what the product page documents, places it in its hearing protection lane, and points to the ranked guides for the head-to-head field.

What the Product Page Documents

Published July 16, 2026 · Last updated July 27, 2026

Best For: corded reusable flanged hearing protection at NRR 25 dB in a low-profile uncorded design.

Not For: non-noise hazards, or noise that earplugs alone can't bring under ~85 dBA (add earmuffs).

Bottom Line: a practical reusable flanged plug at NRR 25 dB — the uncorded low-profile fit suits tight spaces and high-volume single-use.

Where It Earns Its Slot

The honest positioning: reusable flanged hearing protection at NRR 25 dB in a low-profile uncorded design. Rather than restating the listing, this review weighs that intended use against the documented configuration and the alternatives ranked in the linked guides. Our editorial score of 4.6/5 reflects that fit.

Honest Limits

Honest limits start with fit: no hearing protector delivers its label without a verified seal, and this one is no exception. Plan the NRR 25 label at roughly 9 dB of field reduction under OSHA's subtract-7-and-halve estimate, and let your measured exposure — not the box — decide whether it is enough. It protects against noise only — impact, chemical, and other hazards need their own equipment.

Pros and Cons

Alternatives in the Same Lane

• Howard Leight Laser Lite LL-1 Cordless Earplugs — NRR 32
• Howard Leight Maximum Max-1 Cordless Earplugs — NRR 33
• Howard Leight Quiet QD1 Cordless Earplugs, NRR 26 (Reusable
• Howard Leight Maximum Lite Cordless Earplugs, LPF-1 NRR 30 (
• Howard Leight X-TREME XTR-1 NRR 32 ear plugs (Uncorded, Disp
• Howard Leight TrustFit Pod Earplugs, NRR 28 Cordless Push-In
• Howard Leight FirmFit FF-1 Earplugs, NRR 30 Cordless Foam (F
• Howard Leight Multi Max MM-1 Cordless Earplugs — NRR 31
• 3M PELTOR Optime 105 H10A Ear Muffs - NRR 30 Over-the-Head H

Hearing Protection Guides

• Best Ear Plugs for Construction
• Best Ear Muffs for Construction
• When Do You Need Hearing Protection?
• Best Noise-Canceling Headsets
• Construction Site PPE Guide

Browse by Category

• Hearing Protection
• Ear Muffs
• Foam Ear Plugs
• Corded Ear Plugs
• Shooting Hearing Protection
• PPE Care & Accessories

Frequently Asked Questions

General questions about ratings, OSHA limits and fit are answered in the Best Ear Plugs for Construction guide.

The Bottom Line

Rated 4.6/5 on documented spec, configuration, and value. The 3M E-A-R UltraFit 340-4003 Cordless Earplugs — NRR 25 does the job its listing describes — the guides above tell you whether it's the right pick against the field.

Common questions

How do I know the plug is actually sealed?

Use your own voice as the gauge: sealed ears make it boom (the occlusion effect) and mute the room. No boom, no seal — and most of the label rating is absent until you reinsert properly.

When do I need plugs AND muffs together?

When the numbers say so: derate the label (minus 7 dB, halve the rest) and compare against the measured 8-hour exposure. Above 85 dBA after derating, wear plugs and muffs together; the pairing adds roughly 5 dB over the stronger of the two.

How much of the NRR 25 label reaches the ear?

Plan on roughly 9 dB: OSHA's enforcement estimate subtracts 7 dB from the NRR 25 label and halves the remainder. Compare that figure against your measured 8-hour average — and where the result still exceeds 85 dBA, dual protection (plugs under muffs) takes over, not a higher label.

What does the 3M E-A-R UltraFit 340-4003 Cordless Earplugs — NRR 25 listing actually document?

Best For: corded reusable flanged hearing protection at NRR 25 dB in a low-profile uncorded design.…

What are the alternatives to the 3M E-A-R UltraFit 340-4003 Cordless Earplugs — NRR 25?

The sibling ear plugs options linked in this review, ranked head-to-head in the hearing protection guides below — start with the buyer's guides for the field view.

Sources. Requirements referenced here come from OSHA 29 CFR 1910 and the NIOSH recommendations. Where a consensus standard governs, the ANSI document is named in the text.

Related reference

Neighbouring references on this site: 3m ultrafit 340-4002 corded earplugs, reusable - nrr 27 (50 pairs), 3m ultrafit metal detectable corded earplugs, 3m e-a-rsoft superfit 312-1256 cordless earplugs, 3m ear soft yellow neons 312 1250 nrr 33 uncorded 200 pair, what is nrr noise reduction rating explained, and corded vs cordless ear plugs.

Why trust WC Safety

WC Safety is an independent, affiliate-supported review site. It is not a retailer: it holds no inventory, takes no orders, and earns only from qualifying purchases through clearly marked links — which never changes what a product is rated to do. Standards language is taken from the regulation text directly, and ratings are reported as the manufacturer publishes them. We run no laboratory and perform no testing of our own. Where published sources disagree, we say so and plan on the conservative figure rather than the flattering one.

Our methodology

Figures come from the regulation and the published specification, in that order. Derated numbers are calculated, not estimated. Nothing here is presented as a measured result, because we measure nothing.

Researched and written by Steven Eaton, editor of WC Safety. Steven holds no safety certification and does not test products; this page compares what manufacturers and regulators publish, with the gaps in that record marked. Last reviewed August 2026.