iPhone 6 Plus Case, ROCK Luxury Ultra Thin Slim Infinite Beauty Aluminum Alloy Metal Bumper Cover and Clear Back Panel for Apple iPhone 6 Plus (5.5 inch) (Sliver) The backboard is made of hardened acylic material, the backboard is smooth and presents the original beaury of the cellphone with the light transmission as high as 92%. Its 4h Hardness is wear-resisting and scratch-resisting. The metal bumper is made of aviation aluminum alloy with precision techniques, such as heat treatment, high-precision CNC, abrading, ultrasonic cleaning, chemical polishing, sand blast, anodic oxidation, laser, etc. The bumper with symmetric design is smooth and round, it is more comfortable in hand. Microfiber inner offers more portections for phone. Unique hidden back buttom design makes the metal bumper well fit the transparent backboard, it is beautiful and elegant. With embedded button and T-shaped slot, the button is more stable and the product looks exquisite and high-end.