Here’s a high-resolution background image of a chrome chain (and thin metallic wire) over a dark gray reflective surface. It’s a highly versatile 3d rendering that can be used in all sorts of ways: you can integrate it into a banner graphic, website (as part of a “hero” image), powerpoint template, or…pretty much anything where you need to convey a message of strength and security.
I once used this as part of a network security banner I was working on. I ended up modifying it a bit from the version you see here, but I still think this illustration is quite usable as is. One thing that is especially nice about it is the fact that the gray background surface is a solid color without any gradients. That makes it easy to integrate with other images and complex layouts.