Introducing 3M ™ SecureFit ™ Protective Eyewear, 400 Series - Adds New Features! The original 3M ™ SecureFit ™ Protective Eyewear, 200 Series featured the proprietary self-adjusting 3M ™ Pressure Diffusion Temple Technology - a scientific advancement that helps diffuse pressure over the ear, enhancing frame temple comfort while not compromising the security of fit. But the innovation doesn't stop there - Introducing 3M ™ SecureFit ™ Protective Eyewear, 400 Series .