I've used it about 10 times or less. Thank you. Website Citation: 【NELAX Weighted Eye Mask】 A weighted eye mask has newly arrived as a gadget. We have thoroughly pursued comfort while sleeping. ■Joint clinical research with Yamagata University■ It has been proven that blood flow improves and the time spent in non-REM sleep is overwhelmingly longer than with other eye masks due to the relaxation effect. 【Point 1: Light-blocking due to weight】 The weighted eye mask has light-blocking properties due to its weight, contributing to deep and efficient sleep. It supports the maximum efficiency of sleep onset effects through its light-blocking effect. 【Point 2: Deep Pressure】 The eye area is designed with a light weight. It is designed to fit comfortably with the right amount of weight, so you can rest comfortably. 【Point 3: Washable Cover】 You can easily remove the included cover, so you can wash it in the washing machine if it gets dirty. 【Point 4: Adjustable Velcro】 The size can be adjusted with Velcro. You can easily adjust the size to fit your face size.