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Featuring a one-of-a-kind SpringFlex™ temple, Springerdelivers our face-hugging fit in an unprecedented way. The temples adjust to wider facial profiles by gently bending at a built-in pivot point created by a molded spring in the temple itself. Why does this matter? When rigid spectacles are pulled wider than their natural structure to accommodate for wider faces, a bowing or straightening of the lens may take the eyewear out of compliance. The soft thermoplastic rubber TPR temple tips and nosepiece provide all-day comfort. Springer offers our standard anti-fog protection. Also available with smoke lens (BKFLEX-4010S).

Certifications and characteristics

Standard anti-fog performance plus abrasion, chemical, and UV resistance. Meets demanding industry test requirements (ANSI Z87.1+, EN166UV).

Clear lens allows maximum light transmission without changing or distorting vision or colors (91% of light passes through).

Smoke lens provides allover tint for normal outdoor conditions (18% of light passes through).

About the Springer

Springer’s SpringFlex™ temple design can’t be bent out of shape! Bend it at a right angle and watch it spring back to its naturally curved, molded-to-fit-the-face form. The pliable TPR temple tips provide a secure fit without uncomfortable pressure points. Two-piece durable polycarbonate lenses block 99.9% of the sun’s ultraviolet rays.


  • High-gloss polycarbonate frame and nose pad
  • Naturally curved, flexible temples for fit/comfort
  • TPR temple tips and nosepiece in sky blue
  • ANSI-rated hardcoated polycarbonate lenses
  • Standard anti-fog protection

Part Number Anti-Fog Lens Color Frame Color Accent Color
Standard Clear Black Blue


Standard Smoke Black Blue

Roll Up Your Sleeves and Tear In

SPRINGER BKFLEX-4010 Brochure (pdf)

Brass Knuckle Eye Protection Catalog (pdf)