POLICE sunglasses with a silver frame and gradient lenses, a stylish square design. - Brand: POLICE - Model Number: S2759 - Lens Color: Gradient Purple 579B - Case: Includes case - Frame Color: Silver - Style: Square Thank you for viewing. The hinges have a spring mechanism that opens outwards, providing a good fit and preventing them from opening unintentionally. I bought these because I have poor eyesight and wanted to wear them when using contacts, but I rarely had the opportunity, so I've hardly used them, maybe three times.