1. Shelf: medium to large. The glasses feature an adjustable frame that can be fully closed or expanded. Your body size can be determined by the full circumference of your head, considering both the frame and the soft silicone bands. 2. Never lose track of your glasses. The prelens is attached, allowing for quick removal and insertion into a glasses strap. Adjust them to fit or comfortably rest them around your neck when not in use. With this builtin convenience, losing your glasses is no longer a concern. 3. Stay flexible. The adjustable temple function on the frame lets you instantly modify the size. After each use, easily adjust the length for a fit. 4. Dependable features. These readers are built with shockabsorbing lenses, durable silicone, and reinforced pull bars for added stability. The frame can be folded 180 degrees for compact storage or lowered around your neck. Designed for longterm wear, these glasses are made to last for years.