My husband is a technical instructor and is constantly putting on and removing his glasses. I've purchased other glasses holders and while they might be okay for a few weeks or months, most wear out or allow the glasses to slip off after a few wearings. I searched around on Amazon for good ratings and reviews and found this brand. Finally my husband has the solution for his glasses. There's no slippage and it's comfortable to wear around his neck. The filament doesn't get wet or sweaty (it's pretty hot in south Louisiana). It's just a great little product.