PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

ER9Protector,hearing

Rexton Inc · NSN 4240-01-539-6001 · FSC 4240 · No Item Name Available
Verified by PartsTable
NSN 4240-01-539-6001 — this item is cataloged by the U.S. Government under National Stock Number 4240-01-539-6001. Primary manufacturer part number: ER9.
Features
  • Protector,hearing — FSC 4240
  • 1 verified cross-reference
  • Primary manufacturer: Rexton Inc
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Protector,hearing, cataloged under National Stock Number 4240-01-539-6001, is classified within Federal Supply Class 4240 (No Item Name Available) of the Fire Fighting, Rescue, and Safety Equipment group. The primary manufacturer of record is Rexton Inc. This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4240-01-539-6001
Primary Part NumberER9
Item NameProtector,hearing
FSC / FSG4240 / 42 — No Item Name Available
ManufacturerRexton Inc
StatusACTIVE
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
2930-00-073-0472AAX0418 INTERCHANGEABLE
Cap,filler Opening
Stant Mfg Co Inc
4730-00-922-7889214-1309 INTERCHANGEABLE
Clamp,hose
Cnh Industrial America Llc Dba Cnh America
4730-01-269-1439ER9 INTERCHANGEABLE
Spacer,flexible,pipeline
Environmental Systems Llc Dba Environmental Systems Llc
6680-01-516-6569ER-9 INTERCHANGEABLE
Meter,flow Rate Indicating
Badger Meter Inc
Cross-Reference Index
Part NumberManufacturer
ER9 PRIMARY Rexton Inc (USA)
Related Parts
2930-00-073-0472INTERCHANGEABLE
CAP,FILLER OPENING
AAX0418
4730-00-922-7889INTERCHANGEABLE
CLAMP,HOSE
214-1309
4730-01-269-1439INTERCHANGEABLE
SPACER,FLEXIBLE,PIPELINE
ER9
6680-01-516-6569INTERCHANGEABLE
METER,FLOW RATE INDICATING
ER-9

Frequently Asked Questions

What is NSN 4240-01-539-6001?

NSN 4240-01-539-6001 is a Protector,hearing, manufactured by Rexton Inc, classified under FSC 4240 (No Item Name Available). Status: active.

What are the part numbers for NSN 4240-01-539-6001?

NSN 4240-01-539-6001 has 1 cross-referenced part number: ER9 (Rexton Inc).

What NSN replaces 4240-01-539-6001?

There are 4 known substitutes for 4240-01-539-6001: 2930-00-073-0472, 4730-00-922-7889, 4730-01-269-1439 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of ER9?

Key specifications for ER9: Part Name Assigned by Controlling Agency: FILTER EAR DEFENDER. 1 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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