MERC 3(MATERIAL ENGINEERED REINFORCED CHASSIS) Engineered composite and alloy materials reinforce a polycarbonate sub-frame to create a chassis that is rigid and light to resist twisting and bending. CARBON FIBER REINFORCED Aerospace grade carbon fiber used in MERC 3 reinforced chassis design. HIT (HIGH IMPACT TPU) CROWNS Co-molded HIT (High Impact TPU) technology provides extreme protection at both ends. FAST TAP BUTTONS Integrated buttons protect iPhone controls while providing quick and easy use of volume and on/off functions. MIL-SPEC APPROVED Meets military specification drop-test requirements.