Dimension (l.w.h): 104mm x 49mm x 15 mm Buttons: 7, Rush Quiz, A, B, C, D, E, F 11 Activity modules Technology applied: two-way infrared technology Support Self-Paced-Response ID Address Programmable Power required: two 1.5 volt batteries Transmission distance: > 15 meters Transmission angle: > 30 degree Battery life: > 1 to 2 years for ordinary use ENJOY Audience Response System, every one is involved. No one is embarrassed or shy about giving an answer. They're having fun and behind the scenes, ENJOY is correlating all the results, freeing the teacher to teach. Polls can be taken, tests can be graded and reports can be generated - all with the press of a button.