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Larger classrooms require an amplified teacher so that everyone can hear and understand the lesson, and Lightspeed Technologies avoids the hassle of a wired microphone with its Redcat audio system and FlexMike. Capable of reproducing the full range of the human voice, FlexMike weighs less than two ounces and can sit on a lanyard around the teacher’s neck. It has its own volume control and a school day length battery that can be recharged with a Micro-USB cord or two at a time with the $63 Cradle Charger. It’s being used in the San Antonio Independent School District’s 2,500 classrooms.