Accessories

UNDER SHIRT SYSTEM

Name: UNDER SHIRT SYSTEM
Brand: Extrema Ratio
SKU: 04.4100.0220
Price: 26.23 EUR
Availability: InStock

€26.23

Accessory for model N.K.1.It must be fixed to the kydex sheath to wear the knife hiddenly.

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🇮🇹 Made in Italy · ✓ Lifetime warranty · ↩ 14-day returns
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Use

PROFESSIONAL OPERATIONAL DEPLOYMENT

Extrema Ratio develops knives engineered for real-world applications, where control, precision, and reliability are essential requirements. Every model is designed to ensure stable ergonomics, proper balance, and consistent performance, even during prolonged use. Use the tool strictly according to its technical function, avoiding improper use or stress beyond its intended scope. Mindful use preserves safety, efficiency, and longevity, keeping structural and operational characteristics of the product intact.

Want more details? Check the complete guide.

Care

ESSENTIAL ROUTINE MAINTENANCE

Regular maintenance is fundamental to preserving the efficiency, reliability, and lifespan of your product. After each use – especially in the presence of salt water, humidity, mud, or grease residues – rinse with fresh water, dry thoroughly, and apply a suitable lubricant to metal parts and moving mechanisms. Periodically inspect the inside of the sheath, removing sand, dust, or abrasive particles that could damage the blade finish when sheathing or unsheathing.

Want more information? Check the complete guide.

Warranty

OFFICIAL ASSISTANCE AND WARRANTY

Extrema Ratio knives are covered by a lifetime warranty covering defects in workmanship, materials, or treatments that compromise functionality. Sheaths are guaranteed for two years from the first documented purchase. Upon verification of a recognized defect, the product will be professionally repaired. If non-restorable, the tool will be replaced with an identical new product. Should the specific model be unavailable, it will be replaced with the most similar product in terms of technical features and overall value to ensure your complete satisfaction.

Want more details? Read our warranty information.

Frequently bought together

Tactical

N.K.1

04.1000.0123

€139.34

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KIT E.R.S. WITH POCKET

04.4100.0129

€119.67

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DIAMOND SHARPENER

04.4100.0130

€20.49

Sharpeners

DUAL GRIT SHARPENER AND FIRESTEEL POCKET KIT

04.4100.0104

€47.54

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SURVIVAL KIT UK WITH SHEATH

04.4100.0127

€136.89

Tactical

BD4 LUCKY

04.1000.0497

€200.82

Tactical

DMP

04.1000.0219

€259.84

Tactical

N.K.2

04.1000.0204

€129.51

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04.5315.0222/FSB/BLK

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04.4100.0127

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ULTICLIP SLIM 3.3

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