Htc One M9 Screen Protector, Blue Light Filter Tempered Glass - Demomm(tm) High-quality Ultra-thin 9h+ 2.5d Filter Out Eye-fatigue and Eye-strain Causing Blue Light Tempered Glass Protective Film for Htc One M9 (9h+ 2.5d Blue Light) Ideal for children and adults. Filters harmful Blue Light, which can lead to eye-fatigue and eye-strain. Promotes healthy melatonin levels for better sleep. Sensitivity for a natural feel that provides flawless touch screen accuracy. Protects your screen from unwanted scratches