... Wireless Conference System 1. Patent IR technology 2. LCD display screen window 3. 11 Activity modules Tech specs of Wireless Conference System IR118 are ... Self-Paced-ResponseButtons: 16, A/1, B/2, C/3, D/4, E/5, F/6, 7, 8, 9, 0, ., <, >, CE, >>>, ... distance: > 20 metersTransmission angle> 30 degreeBattery life: > 1 to 2 years for ordinary useSupport fast-ID setup functionDurable and not ...