I've dispensed a number of these lately and enjoyed working on them in the finishing lab as well as when adjusting. The screw has been replaced by a post that gets pressed into the hinge, therefore, the post cannot be displaced or fall out because of the tension that holds it in place.

The company says, "...cut from a single sheet of surgical-grade titanium. The unique hinge system is designed without screws or solder-points and the spindle is guaranteed not to loosen or fall out - a guarantee unique to Zero G." From the inside and outside the post/hinge looks like this.

When dis-assembling/assembling for lens glazing, the operation is simple. The post is pressed out using a block cut to hold frame and temple securely. The eyewire is open for grooved lens fitting, temple is attached closing the eyewire opening and the post is pressed back into place. This arrangement allows for lenses only ordered from the lab when the patient wants to use the frame again as long as the lab has a trace of the lens.

Lens replacement would look like this.



Place the endpiece/temple in the slot and press out the post.



Remove the temple, open the eyewire and fit the grooved lens.



Replace temple and press the post all the way into the hinge.



For more information, see www.zerogeyewear.com