| we can supply Audienc Response SystemHere are brief introduction of our company:We specialize in designing, developing,and producing educational technology products.Our main product is ENJOY Audience Response System (or Classroom Performance System,or Student Response System),which has been successfully used in multimedia classrooms and conference rooms home and abroad.2.4GHz digital RF technology LED status:green and red 4 radios channels 11 Activity modules Support Self-Paced-Response ID Address Programmable Power required: two 1.5 volt batteries Transmission distance: > 100 meters Transmission angle: > 360 degree Battery life: > 1 to 2 years for ordinary use | 
