The USN Endura® 4 shown open and closed

USN Endura® 4


$119.95 MSRP

Technical Specs

Spyderco is known for our involvement with our ELUs (End Line Users). Our participation on Forums both on our own site and others is something we take pride in and enjoy. The members who spend their time with us get a unique perspective into Spyderco and we get to interact with people who are truly passionate about what we do. Our participation on the Usual Suspect Forum led to the creation of a very special, one of a kind knife, the Spyderco USN Endura4 in Toxic Green. After months of discussion it was settled that the USN Endura 4 would not only be Toxic, but that it would include some of the most popular attributes found in the Endura 4 lineup.

If knives could be created in the same way we choose players for fantasy football league teams, every hardcore knife knut would recruit features and characteristics they like best from different knife companies and combine them into their favorite knife.  Spyderco undoubtedly fulfilled many knife knuts knife fantasy picks with the introduction of the Endura with Emerson's opening feature; combining all that's functional and performance-based in a Spyderco folder with the blade-opening feature made popular and patented by Ernest Emerson of Emerson Knives.

The Emerson opening feature is a hook curving out the top of the knife's blade. When removing the knife from a front pocket it catches the pocket's edge quickly opening the knife blade ready to use. The knife can also be taken out of the pocket without engaging the opening feature by pulling it straight up and out with your fingers on top of the closed blade.

The USN Endura also features all screw construction making cleaning and adjusting easier. Toxic Green fiberglass reinforced nylon handles are molded with Bi-Directional Texturing™ for traction and improved ergonomics. Inside the handle dual skeletonized stainless steel liners strengthen the knife without additional weight and create an anchor for external and internal components to attach through for more sturdiness and rigidity.

The flat saber-ground CombinationEdge™ VG-10 blade is non-reflective, coated with black titanium carbonitride; includes a strong tip and larger 13mm opening hole. The front of the blade features the Usual Suspects logo. Added to the blade's spine is slip resistant jimping. Phosphor bronze washers smooth out the open/close action and the clip is a four-way tip-up, tip-down, left- or right-handed clip.

Spyderco would like to thank the members of Usual Suspect Forum for their continued support. This one's for you!

Overall Length
8.75" (222mm)
Blade Length
3.75" (96mm)
Closed Length
5" (127mm)
Edge Length
3.438" (88mm)
3.6oz (103g)
Blade Thickness
.125" (3mm)
Clip Position
Tip Carry Position
Lock Type

Privacy, Security, and Returns

Accessibility Statement

By purchasing or receiving any item produced by Spyderco, Inc., the owner assumes the responsibility to research and comply with all applicable federal, state, local, and international laws related to the possession, ownership, carry, shipment, transport, and use of any Spyderco product. The owner expressly agrees to indemnify and hold harmless Spyderco, Inc. for all claims resulting directly or indirectly from the purchase, possession, ownership, transportation, or use of the item in violation of applicable federal, state and local laws or regulations. Spyderco is not liable for the misuse of any Spyderco knife or product purchased either directly from Spyderco or a reseller. You must be eighteen (18) years of age to purchase Spyderco knives.

All rights reserved. All product names, art and text herein are the property of Spyderco, Inc. and may not be reproduced in part or whole without the sole written permission of Spyderco, Inc.
Please note, images shown on may be of Production Prototypes. Modification of products, materials, measurements, technical specifications and availability can occur.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.